High Precision Laser Beam Welding and Brazing - New Technologies and Components for Quality Assurance - Geiger, Manfred; Deinzer, Günter; Hanebuth, Henning (Proc. of the 75th Annual Convention of the American Welding Society, 1994)
LFT Import::2019-08-05 (466)

High quality laser cuts with the aid of on-line diagnostics - Geiger, Manfred; Biermann, Stefan; Nuss, Rudolf (CLEO 88 - Conference on Lasers and Electro-Optics, 25-29. April, Anaheim, Ca., 1988)
LFT Import::2019-08-05 (279)

High-resolution inspection of tools for novel forming processes by an endoscopic fringe projection system - Hinz, L.; Schulte, Robert; Kästner, M.; Reithmeier, E. (Optics InfoBase Conference Papers, 2020)
The inspection of tools in sheet-bulk metal forming poses special challenges for metrology. By using a fiber-optic fringe projection system, filigree, internal structures can be measured and the wear can be described by comparison with previous measurements.
CRIS-Team Scopus Importer:2024-12-16

High-temperature-forming of aluminium foam for application in sandwich components - Hahn, Markus; Otto, Andreas (Cellular Metals and Polymers. Proceedings of the Symposium Cellular Metals and Polymers, 2004)
LFT Import::2019-08-05 (1067)

High Temperature Laser Based Drop on Demand Micro Joining of Thin Metallic Layers or Foils using Bronze Braze Preforms - Stein, Stefan; Heberle, Johannes; Suchy, Michael; Tenner, Felix; Hugger, Florian; Roth, Stephan; Schmidt, Michael (Journal of Laser Micro Nanoengineering, 2016)
In this paper a drop on demand based method of joining metallic layers of about 20 μm thickness with Cu-conductors of 100 μm diameter is presented. The process is based on melting spherical preforms of copper based braze (CuSn12) with a liquidus temperature of 990 °C [1]. In the process, a braze preform is induced into a ceramic capillary, molten by a laser pulse and expelled out of the machining head via nitrogen overpressure. After a flight phase the braze droplet wets the surface of the electrode structure and the copper resulting in a firm joint after solidification. The shear strengths of the joints were measured to be 31 MPa for joints on Al2O3 substrates and 37 MPa for joints generated on LTCC substrates with screen printed Ag electrode structures. The shear strengths after temperature shock tests according to DIN EN 60068-2-14 indicate good performance of the joints in harsh environments. The average resistivity of a joint was tested by four wire testing and found to be 1.56 ± 0.33 mΩ. The introduced setup is capable to join thin metallic layers of 30 - 15 μm thickness with cu conductors of 100 μm diameter without the need of flux.
Keywords: micro joining; laser droplet brazing; joining of foils; electronics; contacting; electrodes

High-temperature processing of aluminium foam - Hahn, Markus; Otto, Andreas; Geiger, Manfred (MetFoam 2003, Cellular Metals and Metal Foaming Technology. Proceedings of the 3rd International Conference on Cellular Metals and Metal Foaming Technology, 2003)
LFT Import::2019-08-05 (963)

High-tempreature-forming of cellular aluminium - Hahn, Markus; Otto, Andreas (Cellular Metals and Metal Foaming Technology. Proceedings of the 2nd International Conference on Cellular Metals and Metal Foaming Technology (MetFoam2001), 2001)
LFT Import::2019-08-05 (839)

Hochdruck-Blechumformung mit formlos festen Stoffen als Wirkmedium - Grüner, Martin (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2014)
Using small ceramic spheres as forming medium for blank hydroforming processes allows combining benefits of hydroforming and warm forming of ultra high strength steel. Especially the advantageous leakage behavior of granular material compared to gases and fluids allows a significant reduction of blankholder forces and thereby an increase in moldin

Hochleistungsbauteile durch Kaltmassivumformung hochfester, druckaufgestickter Stähle - Noneder, Johannes; Merklein, Marion; Engel, Ulf; Frank, M.; Frank, J.; Ritzenhoff, R.; Egerer, E. (UTF-Science, 2012)
LFT Import::2019-07-29 (1866)

Hochtemperatur - Umformung von zellularem Aluminium - Hahn, Markus; Otto, Andreas (Materialwissenschaft und Werkstofftechnik, 2000)
LFT Import::2019-07-15 (777)

Homogenisierung von Laserstrahlen - Völkl, Ralf; Zimmermann, M. (Photonik, 2006)
LFT Import::2019-07-16 (1294)

Hot Stamping – Manufacturing functional optimized components - Merklein, Marion; Svec, Thomas (Production Engineering, 2013)
LFT Import::2019-07-29 (1842)

Hot Stamping of Boron Steel Sheets with Tailored Properties: a Review - Merklein, Marion; Wieland, Michael; Lechner, Michael; Bruschi, Stefania; Ghiotti, Andrea (Journal of Materials Processing Technology, 2016)
The paper gives a review of the main research activities recently carried out in the framework of hot stamping of boron steel sheets with tailored properties. The focus is on the process variants developed to locally adjust the mechanical properties of the hot stamped component as well as on the testing and modeling techniques needed to calibrate the numerical models of the tailored tempering processes and to evaluate the post-forming properties of the stamped products.
LFT Import::2019-07-29 (2121)
Keywords: Hot stamping; Tailored properties; Tailored tempering

Hot stamping of ultra-high strength steel parts - Mori, Ken-Ichiro; Bariani, P. F.; Behrens, B. -A.; Brosius, Alexander; Bruschi, Stefania; Maeno, Tomoyoshi; Merklein, Marion; Yanagimoto, J. (CIRP Annals - Manufacturing Technology, 2017)
The demand for new processes to produce high strength parts, under appropriate cost and productivity, has grown with weight reduction and crash safety improvements in automobile design. The hot stamping processes of quenchable steel sheets potentially offer not only small forming load and high formability, but also high strength and no springback by die quenching. This paper aims to provide an overview of the state-of-the-art in such hot stamping processes, including quenchability, formability, heating and cooling approaches and lubrication. The paper also includes a description of the mechanism of formability and quenching, tailoring, analysis of hot stamping processes and applicability.
CRIS-Team Scopus Importer:2023-03-29
Keywords: Forming; Hot stamping; Sheet metal

Hot stamping of ultra high strength steels as a key technology for lightweight construction - Lechler, Jürgen; Merklein, Marion (Tagungsband Material Science & Technology Conference MS&T’08, 2008)
Due to increased usage of high strength steels in scope of lightweight construction design in this context thermal assistant forming technologies like hot stamping of boron-manganese steels of the type 22MnB5 obtained more and more industrial relevance in the last five years. For a reliable process design the knowledge of the material properties in dependency of the process influencing characteristics and hereby mainly the temperature displays a base requirement. In the following publication an overview will be given about different experimental methodologies developed at the Chair of Manufacturing technology for being capable to investigate the material behavior according to the typical time-temperature profile of hot stamping. Furthermore, main experimental results acquired regarding the thermal, the mechanical and the tribological properties of 22MnB5 will be exemplarily shown as well. © 2008 MS&T'08 ®.
LFT Import::2019-08-05 (1550)
Keywords: 22MnB5; Hot stamping; Material properties; Modeling

Hot Stamping - Process Window for the Austenitization of a Dualphase Steel - Svec, Thomas; Merklein, Marion (4th International Conference Hot Sheet Metal Forming of High-Performance Steel, 2013)
LFT Import::2019-08-05 (1900)

How dry is dry? - A critical analysis of surface conditions used in dry metal forming - Tenner, Jennifer; Almohallami, A.; Arghavani, M.; Böhermann, F.; Freiße, H.; Herrmann, M.; Mousavi, S. A.; Schöler, S.; Scholz, P.; Teller, M. (Dry Metal Forming Open Access Journal, 2017)
LFT Import::2019-07-29 (2240)

Hybrid Additive Manufacturing Technologies - An Analysis regarding Potentials and Applications - Merklein, Marion; Junker, Daniel; Schaub, Adam; Neubauer, Franziska (Physics Procedia, 2016)
Imposing the trend of mass customization of lightweight construction in industry, conventional manufacturing processes like forming technology and chipping production are pushed to their limits for economical manufacturing. More flexible processes are needed which were developed by the additive manufacturing technology. This toolless production principle offers a high geometrical freedom and an optimized utilization of the used material. Thus load adjusted lightweight components can be produced in small lot sizes in an economical way. To compensate disadvantages like inadequate accuracy and surface roughness hybrid machines combining additive and subtractive manufacturing are developed. Within this paper the principles of mainly used additive manufacturing processes of metals and their possibility to be integrated into a hybrid production machine are summarized. It is pointed out that in particular the integration of deposition processes into a CNC milling center supposes high potential for manufacturing larger parts with high accuracy. Furthermore the combination of additive and subtractive manufacturing allows the production of ready to use products within one single machine. Additionally actual research for the integration of additive manufacturing processes into the production chain will be analyzed. For the long manufacturing time of additive production processes the combination with conventional manufacturing processes like sheet or bulk metal forming seems an effective solution. Especially large volumes can be produced by conventional processes. In an additional production step active elements can be applied by additive manufacturing. This principle is also investigated for tool production to reduce chipping of the high strength material used for forming tools. The aim is the addition of active elements onto a geometrical simple basis by using Laser Metal Deposition. That process allows the utilization of several powder materials during one process what enables the tailoring of the tools materials mechanical properties. Another aspect is the possibility of Laser Alloying of the tools surface to reduce abrasive and adhesive wear. This technique is especially interesting for tools used in hot stamping production.
LFT Import::2019-07-29 (2265)
Keywords: additive manufacturing; hybrid processes; process combination

Hybride Bauteile, Werkzeuge und Prozessketten – Anwendungen der Kombination aus Additiver Fertigung und Umformtechnik - Papke, Thomas; Huber, Florian; Hafenecker, Jan; Schmidt, Michael; Merklein, Marion (7. Industriekolloquium des Sonderforschungsbereichs 814 - Additive Fertigung, 2019)

Hybrid process chains combining metal additive manufacturing and forming – A review - Hafenecker, Jan; Bartels, Dominic; Kuball, Clara-Maria; Kreß, Maximilian; Rothfelder, Richard; Schmidt, Michael; Merklein, Marion (CIRP Journal of Manufacturing Science and Technology, 2023)
Mass production of customized parts using conventional manufacturing technologies is challenging. The increasing use of hybrid approaches is a promising way to address mass customization. Due to the widespread use of the term hybrid in manufacturing technologies, the amount of literature is increasing dramatically. Therefore, this paper aims to provide an overview of the current state of the art on the combination of additive manufacturing (AM) and metal forming. First, the term hybrid is classified, followed by examples of hybrid AM. The focus of this paper is on the combination of either sheet metal forming or bulk metal forming with either powder bed fusion or directed energy deposition. Examples of both sequences - AM before or after forming - are presented and analyzed for their potential use in hybrid parts. From the selected literature, the possibilities of this approach are derived as well as the ongoing need for future research. AM offers great potential for adjusting the microstructure and resulting material properties to improve formability. Furthermore, forming operations need to be adapted to the different material properties found in hybrid part
Keywords: Hybrid manufacturing Hybrid processes Hybrid parts Additive manufacturing Sheet metal forming Bulk metal forming Review paper

Hydroformen mit hochviskosen Medien - Dal Bò, Paolo (Blech, Rohre, Profile, 2004)
LFT Import::2019-07-16 (1111)

Hydroforming in Patchwork Blanks - Numerical Modeling and Experimental Validation - Lamprecht, Klaus; Merklein, Marion; Geiger, Manfred (Proceedings of the 6th International Conference and Workshop on Numerical Simulation of 3D Sheet forming Processes (NumiSheet), 15.-19.08., Detroit, USA, 2005)
LFT Import::2019-08-05 (1139)

Hydroforming of Deep-Drawn Preforms? A Novel Approach Towards Innovative Sheet Metal Components - Geiger, Manfred; Lamprecht, Klaus (Production Engineering - Annals of the WGP, 2006)
LFT Import::2019-08-05 (1270)

Hydroforming of High-Strength Aluminum Tubes with Thermo-Mechanical Manufacturing Processes - Trân, Ricardo; Reblitz, Jonas; Haase, Rico; Psyk, Verena; Kräusel, Verena; Merklein, Marion (Engineering Proceedings, 2022)
The amount of complex profile components in car bodies increases due to the emerging electromobility. High-strength aluminum alloys are ideally suited as material for automotive applications due to their extraordinary lightweight construction potential. The presented study focuses on the transfer of established thermo-mechanical manufacturing processes for sheet metal components to hydroforming of tube material. Demonstrator components are produced from EN AW-7020 using W-temper-forming and hot forming and compared numerically and experimentally. The results show that the determined material properties are sufficiently accurate to numerically represent the temperature-supported processes with excellent precision. The formed components can be used to demonstrate the potential of hydroforming for high-strength aluminum tubes using W-temper-forming and hot forming.
Created from Fastlane, Scopus look-up
Keywords: aluminum; finite element method (FEM); heat treatment; hydroforming; metal forming

Hydroforming of Inhomogeneous Sheet Pairs with Counterpressure - Geiger, Manfred; Merklein, Marion; Cojutti, Massimo (Production Engineering Research and Development, 2008)
LFT Import::2019-07-29 (1544)

Hydroforming of Laser Welded Tailored and Patchwork Blanks - Tolazzi, Massimo; Lamprecht, Klaus; Geiger, Manfred (LANE, 2007)
LFT Import::2019-08-05 (1441)

Hydroforming of Sheet Metal Pairs - Geiger, Manfred; Vollertsen, Frank; Hein, Philipp (Sheet Metal 1998: Proceedings of the 6th International Conference on Sheet Metal, 1998)
LFT Import::2019-08-05 (1599)

Hydroforming of Sheet Metal Pairs for the Production of Hollow Bodies - Vahl, Meik; Bobbert, S.; Hein, Philipp (Revue de Métallurgie, 2000)
LFT Import::2019-07-15 (805)

Hydroforming of sheet metal pairs from aluminium alloys - Novotny, Stefan; Hein, Philipp (Journal of Materials Processing Technology, 2001)
New production technologies like the hydroforming of sheet metal pairs have to be qualified for both steel and aluminium alloy sheets. While good mechanical properties and the excellent recyclability make sheets from aluminium alloys a good choice of material for lightweight construction, the lower formability compared to steel sheets raises various challenges for part manufacturing. Forming problems in the hydroforming process arise not so much from the material properties that determine the shape of the flow curve like the flow stress or the hardening exponent (n-value), but especially from the anisotropy of the aluminium material. This paper shows the process window, special requirements and potentials of the hydroforming of sheet metal pairs, using sheet material from heat treatable aluminium alloy AA 6016-T4. Different approaches for the enhancement of the formability of this material in the hydroforming process are outlined. © 2001 Elsevier Science B.V. All rights reserved.
LFT Import::2019-07-15 (909)
Keywords: Aluminium; Elevated temperature; Hydroforming; Lightweight construction

Hydrogen release from liquid organic hydrogen carrier using plate catalysts in continuous and dynamic operation - Nathrath, Phillip; Baier, Benjamin; Herz, N; Wituschek, Simon; Raed Ramzi, Yousuf; Merklein, Marion; Li, M.; Lederle, F.; Wasserscheid, Peter; Hübner, E.G.; Schühle, Patrick (Chemical Engineering Journal, 2025)
Significant fluctuations in energy supply are anticipated with the increasing utilization of renewable energy sources. To mitigate these fluctuations, green hydrogen released from Liquid Organic Hydrogen Carrier (LOHC) systems offers a promising solution. The use of plate catalysts in novel continuous reactor configurations enables favorable heat and mass transfer rates to drive this highly endothermic hydrogen release reaction. These catalytic plate reactors facilitate dynamic operation modes for an effective response to rapid changes in hydrogen and energy demand. In this study the performance of an established spray-coated plate catalyst is tested for the first time in continuous and dynamic operation modes. In detail, the productivity in hydrogen release from the LOHC-molecule perhydro benzyltoluene (H12-BT) is determined using a catalytic plate reactor and a tailored restart protocol was developed to maintain high hydrogen release productivities after a reactor shutdown. The plate catalysts showed good activity of up-to 0.25 mgH2 min−1 cm−2, a highly dynamic response in hydrogen release and an excellent stability under stationary and fluctuating conditions. Furthermore, a novel non-additive manufacturing method for plate catalysts through laser-texturing is introduced. The morphology of these new structures is characterized and their dehydrogenation performance is compared to the superior spray-coated benchmark.
CRIS-Team Scopus Importer:2025-02-07
Keywords: Benzyltoluene; Dehydrogenation; Laser-texturing; LOHC; Plate reactor

Identification of a process window for tailored carburization of sheet metals in hot stamping - Horn, Alexander; Merklein, Marion (AIP Conference Proceedings, 2018)
LFT Import::2019-07-29 (2299)

Identification of Process-Based Limit Stress States Applying a Stretch-Bending-Test - Hezler, Christian; Merklein, Marion; Hecht, Joachim; Griesbach, Bernd (Key Engineering Materials, 2012)
The evaluation of forming simulation by using the forming limit curve has only limited validity if it is applied on car body components with non-linear strain paths. If modern high strength materials are used, the forming limit criteria can also provide invalid predictions. Especially high strength multiphase steels show a specific behaviour in forming, necking and crack initiation. If bending loads are applied to these materials, the onset of cracking occurs partially not within the range of the forming limit curve (FLC). The stress limit indicates the failure beginning more accurate. It is independent of the forming history and should be less sensitive to the behaviour of high strength steels. In the post processing of a simulation it could be used similar to the forming limit. A limit curve applied on the in-plane-stress-diagram of an analysed component defines areas that are more vulnerable for cracking. The required stress limit curve will be obtained in this research by applying a stretch-bending-test. It is selected in order to reach loads, which are comparable to the forming process in the components' production. The forming state that is affecting the specimen is a combination of bending and stretching load. Different load conditions can be applied at the test by altering the stamp-radius and the specimen geometry. Since stresses cannot be measured directly in the experiment, the test is modelled in the simulation where the stresses can be calculated for a given material model. Finally the stress limit criterion was applied on the test parts' stress distribution diagram. Occurring stresses above the stress limit curve are displayed on the simulation. Thereby it is possible to show a good correlation in critical areas between the failure prediction in the simulation and occurring rupture on the test component. © (2012) Trans Tech Publications.
LFT Import::2019-07-29 (1786)
Keywords: High strength steels; Process-orientated characterisation; Stress limit criteria; Stretchbending- test

Identification of tribological mechanisms of shot peened steel surfaces for an application in sheet-bulk metal forming - Löffler, Maria; Engel, Ulf; Andreas, Kolja; Merklein, Marion (Proceedings of the 13th International Conference on Shot Peening, 2017)
LFT Import::2019-08-05 (2254)

Identifikation von Modellparametern zur Bestimmung des Fließ- und Verfestigungsverhaltens unter Berücksichtigung einer Belastungsumkehr - Kaupper, Markus; Merklein, Marion (Bauteile der Zukunft - Methoden und Prozesse - Tagungsband T31 des 30. EFB-Kolloquiums Blechverarbeitung am 2. und 3. März 2010 in Bad Boll, 2010)
LFT Import::2019-08-05 (211)

Idroformatura di lamiera per strutture complesse - Geiger, Manfred; Tolazzi, Massimo (Lamiera, 2005)
LFT Import::2019-07-16 (1209)

Impact of Coating Systems on the Tribological and Wear Behavior of Hot Stamping Tools - Merklein, Marion; Wieland, Michael (Proc. 4th Int. Conf. on Tribology in Manufacturing Processes (ICTMP), 2010)
LFT Import::2019-08-05 (307)

Impact of liquid lubricant on the flattening behaviour of single asperities - Weidel, Stephan; Engel, Ulf (Proceedings of the 3rd International Conference on Multi-Material Micro Manufacture, 2007)
LFT Import::2019-08-05 (1496)

Impact of optical strain rate controlling on the determination of mechanical sheet metal properties - Naumann, David; Merklein, Marion (6th MATFEM Conference, 2024)
A key aspect of state of the art part, tool and process development is the prediction quality of numerical simu- lations. Costs and time in the design process can be reduced only with sufficiently reliable results. To obtain meaningful results, precise material data is an important input variable. In the state of the art material characteri- zation with universal testing machines, material beha- vior is either determined at constant crosshead speed or at constant strain rates, only in the elastic region, accor- ding to ISO 6892-1 for tensile tests. Due to the fact, that commercial simulation software expects strain hardening data at constant strain rates, an error is made with current characterization tests at non-constant strain rates, due to the strain rate sensitivity that most metals exhibit. To obtain constant strain rate material data, optical controlled characterization tests can be conducted. In the scope of this research, an optical strain rate con- trolled tensile testing method was developed for and ap- plied to uniaxial tensile tests to investigate its influence on the measurement of mechanical properties of typical drawing grade steels. Therefore, displacement strain rate controlled (DSRC) and optical strain rate controlled (OSRC) tensile tests at room temperature with a nomi- nal strain rate of 0.004 1/s were conducted and evalua- ted. Flat specimens according to ISO 6892-1 with a gauge length of 80 mm were used. The tests were per- formed with a universal testing machine (ZwickRoell GmbH & Co. KG.) and the strain was measured and controlled with a 3D DIC System (GOM ARAMIS 12M SRX). The both commercial common steels DP600 (CR330Y590T-DH) and DC05 (CR4) at a nominal thickness of 1.2 mm were analyzed regarding strain rate evolution during tensile testing and how OSRC influences the strain rate development. The OSRC-method shows the potential to obtain materi- al data in material testing at constant strain rates over the complete tensile testing trial from the elastic area to ✻ the failure of the specimen. For both investigated steels DP600 and DC05, the influence of the testing method is negligibly small. The root mean squared error of the av- eraged strain rates for DP600 and DC05 was decreased from 0.011 respectively 0.012 to 2.4·10-5 respectively 5.6·10-5 with the OSRC-method. In future work, an adaptive strain rate controlling will be developed, to obtain material data to higher strains in the area of dif- fuse necking. This can be applied to testing at elevated temperatures with e.g. electrically conductive specimen heating, where necking starts at an early stage due to inhomogeneous specimen tempera
Keywords: strain rate controll; DIC; material characterization

Impact of the parameter distribution on the predictive quality of metamodels for clinch joint properties - Einwag, Jonathan-Markus; Mayer, Yannik; Götz, Stefan; Wartzack, Sandro (SheMet2025, 2025)
The growing significance of lightweight design, reveals drawbacks of conventional joining processes such as welding, which are known to consume a considerable amount of energy. This fosters the use of mechanical joining processes including clinching. However, the lack of universally applicable design methods results in a cost- and time-intensive design process. The utilization of machine learning methods can overcome these drawbacks. To ensure a reliable clinch joint design, inherent uncertainties of the design parameter such as tool deviations need to be considered in the design process. Varying distributions of design parameters, due to changes in the manufacturing process, can lead to high-computational effort in recalculating the resulting clinch joint properties with numerical simulations. Current metamodel-based methods for consideration of inherent uncertainties within the design parameters do not investigate the transferability of metamodels to different distributions of design parameters, which can lead to incorrect predictions. Therefore, this contribution investigates the performance of several metamodels on differently distributed design parameters. The obtained results indicate that metamodels demonstrate the best performance when training and evaluation distributions are identical and that polynomial regression models perform best on disparate distributions, when trained on uniform distribution
Keywords: Uncertainty; Machine Learning; Mechanical Joining

Improved Deep Drawability of Aluminium Blanks by Local Laser Heat Treatment - Kerausch, Michael; Merklein, Marion; Geiger, Manfred (Laser Assisted Net shape Engineering 4. Proceedings ot the 4th LANE, 2004)
LFT Import::2019-08-05 (1066)

Improved fatigue strength of cold forging tools by surface and coating technologies - Hinsel, Christian; Celeghini, Martino; Engel, Ulf; Geiger, Manfred (Advanced Technology of Plasti¬city 1990, Proc. of the 6th Int. Conf. on Technology of Plasticity, Vol. 1, 1999)
None
LFT Import::2019-08-05 (1996)

Improved Formability of Aluminum Alloys using Laser Induced Hardening of Tailored Heat Treated Blanks - Nguyen Hung,; Merklein, Marion (Physics Procedia, 2012)
LFT Import::2019-07-29 (1861)
Keywords: Forming limit; Laser hardening; Laser radiation; Layout design; Tailored Heat Treated Blanks

Improved material flow for deep drawing of aluminium blanks by local laser heat treatment - Kerausch, Michael; Merklein, Marion; Geiger, Manfred (Proceedings of the 10th International Conference on Sheet Metal, She Met, 2003)
LFT Import::2019-08-05 (952)

Improved Roller Hemming System for High Volume Part Production - Zubeil, Martin; Roll, Karl; Merklein, Marion (Key Engineering Materials, 2011)
Roller hemming is usually applied for hang-on-parts such as hoods, doors or trunk-lids which all have complex non-linear geometries. The flange is often hemmed along both surfaces and edges which have 3D curvilinear shapes. Minimization of hemming defects and the requirement to improve cycle time of the roller hemming process are essential for roller hemmed hang-on-parts in the automotive industry. Different systems such as the driven roller hemming provide the possibility to increase the strain rate without loosing surface quality and dimensional stability. Investigating the influence of friction during roller hemming, results will give an understanding of the advantage for mentioned roller hemming systems. © (2011) Trans Tech Publications.
LFT Import::2019-07-29 (1749)
Keywords: Design of experiments method; Driven roller hemming system; Finite element method; Friction; Roller hemming; Tandem roller hemming system

Improved Sheet Bulk Metal Forming Processes by Local Adjustment of Tribological Properties - Hetzner, Harald; Koch, Johannes Peter Karl; Tremmel, Stephan; Wartzack, Sandro; Merklein, Marion (Journal of Manufacturing Science and Engineering, 2011)
This paper is focused on a combined deep drawing and extrusion process dedicated to the new process class of sheet bulk metal forming (SBMF). Exemplified by the forming of gearings, combined sheet and bulk forming operations are applied to sheet metal in order to form local functional features through an intended and controlled change of the sheet thickness. For investigations on the form filling and the identification of significant influencing factors on the material flow, a FE simulation model has been built. The FE model is validated by the results of manufacturing experiments using DC04 with a thickness of 2.0 mm as blank material. Due to the fact that the workpiece is in extensive contact to the tool surface and that the pressure reaches locally up to 2500 MPa, the tribological conditions are a determining factor of the process. Thus, their influence is discussed in detail in this paper. In the first instance, different frictional zones having a distinct effect on the resulting material flow are identified and their effect on improved form filling is demonstrated. Subsequently, a more comprehensive methodology is developed to define tribological zones of forming tools. For this, a system analysis of the digital mock-up of the forming process is performed. Besides friction, other relevant aspects of forming tool tribology like contact pressure, sliding velocity, and surface magnification are considered. The gathered information is employed to partition the tools into tribological zones. This is done by systematically intersecting and re-merging zones identified for each of the criterion. The so-called load-scanning test allows the investigation of the friction coefficient in dependence of the contact pressure and possible loading limits of tribological pairings. It provides an appropriate tribological model test to evaluate tribological measures like coatings, surface textures and lubricants with respect to their targeted application in particular zones. The obtained results can be employed in the layout of further forming processes to reach the desired process behavior. This can be, for example, an improved form filling, less abrasive wear and adhesive damage or lower forming forces, respectively tool load for an improved durability of the die.
UnivIS-Import:2015-03-09:Pub.2011.tech.FT.FT-KLMEFK.improv
Keywords: load-scanning test; material flow; sheet bulk metal forming; tribology

Improved Tool Performance in Microblanking of Thin Metal Foils Through Defined Cutting Edge Modification of Silicon Punches - Hildering, Sven; Engel, Ulf; Merklein, Marion (Proc. 4M/ICOMM2015 Conf., 2015)
LFT Import::2019-08-05 (2087)

Improved Tribological Behavior of Cold Forging Tool Surfaces by Excimer Laser Micro Texturing - Geiger, Manfred; Popp, Uwe; Engel, Ulf (Production Engineering, 2002)
LFT Import::2019-07-16 (1679)

Improvement of a rivet geometry for the self-piercing riveting of high-strength steel and multi-material joints - Uhe, Benedikt; Kuball, Clara-Maria; Merklein, Marion; Meschut, Gerson (Production Engineering, 2020)
As a result of lightweight design, increased use is being made of high-strength steel and aluminium in car bodies. Self-piercing riveting is an established technique for joining these materials. The dissimilar properties of the two materials have led to a number of different rivet geometries in the past. Each rivet geometry fulfils the requirements of the materials within a limited range. In the present investigation, an improved rivet geometry is developed, which permits the reliable joining of two material combinations that could only be joined by two different rivet geometries up until now. Material combination 1 consists of high-strength steel on both sides, while material combination 2 comprises aluminium on the punch side and high-strength steel on the die side. The material flow and the stress and strain conditions prevailing during the joining process are analysed by means of numerical simulation. The rivet geometry is then improved step-by-step on the basis of this analysis. Finally, the improved rivet geometry is manufactured and the findings of the investigation are verified in experimental joining tests.
CRIS-Team Scopus Importer:2020-08-07
Keywords: Aluminium; High-strength steel; Joining technology; Multi-material design; Rivet geometry; Self-piercing riveting

Improvement of axial sliding in the tube hydroforming process of long components due the reduction of friction by high viscous fluid flow - Geiger, Manfred; Dal Bò, Paolo (Proceedings of the 8th ESAFORM Conference on material forming, 27.-29. April 2005, Cluj-Napoca, Romania, 2005)
LFT Import::2019-08-05 (1194)

Improvement of deep drawability of ultra-fine grained 6000 series aluminum alloy by tailored heat treatment - Herrmann, Jürgen; Merklein, Marion (Procedia Manufacturing, 2018)
Among other approaches like alloying, it is possible to increase the strength of aluminum sheet material by the application of processing techniques like Accumulative Roll Bonding. However, the ductility will be reduced, which results in a limited formability in deep drawing operations. In this context, the Tailor Heat Treated Blanks technology is a well-known approach to enhance the forming limits of conventional precipitation hardenable aluminum alloys. The local softening of a blank can be achieved by a short-term heat treatment, which causes a dissolution of the MgSi-clusters in the heat treated zones. In a subsequent deep drawing operation, the material flow can be improved from the softened towards crack-critical areas. Within this investigation, the method of Tailor Heat Treated Blanks is transferred to a multi-layered, ultra-fine grained sheet material of the aluminum alloy AA6014 in order to investigate the effect of a local short-term heat treatment on the forming limits in deep drawing. In a first step, a material characterization in dependency of different heat treatment temperatures is carried out. The strength and ductility, as well as the bond strength of the multi-layered sheets, are investigated. Concluding, the effect on the formability is examined by deep drawing experiments on cylindrical cups in combination with a local heat treatment of the outer flange area prior to the forming step. The results regarding the limiting drawing ratio are compared with a conventional sheet material in the T4 temper condition and a multi-layered sheet material without heat treatment. The investigations indicate that the drawability can be enhanced significantly by the combination of both methods.
LFT Import::2019-07-29 (2318)
Keywords: Accumulative roll bonding; Aluminum alloy; Deep drawing; Laser; Sheet metal; Tailor heat treated blanks

Improvement of Formability in Tube Hydroforming by Reduction of Friction with a High Viscous Fluid Flow - Geiger, Manfred; Vollertsen, Frank; Dal Bò, Paolo (Production Engineering, 2006)
LFT Import::2019-07-16 (1253)

Improvement of numerical modelling considering plane strain material characterization with an elliptic hydraulic bulge test - Lenzen, Matthias; Merklein, Marion (Journal of Manufacturing and Materials Processing, 2018)
LFT Import::2019-07-29 (2288)

Improvement of process control in sheet metal forming by considering the gradual properties of the initial sheet metal - Zettl, Bastian; Schmid, Harald; Pulvermacher, Samuel; Dyck, Alexander; Böhlke, Thomas; Gibmeier, Jens; Merklein, Marion (SAGE Open, 2023)
In scientific studies, sheet metal is usually considered as a two-dimensional body. Thus, it is accepted that material properties are in most cases regarded homogeneous in thickness direction. However, a gradation of certain properties becomes apparent when going beyond the standard characterization methods for sheet metals, which can for example, influence the springback behavior and the thinning of the sheet after forming. Thus, the aim of this work is to further improve the prediction accuracy of springback after forming in simulations, by implementing several inhomogeneous properties over the sheet thickness in an existing material model. For this purpose, the entire procedure from the identification of the inhomogeneous properties for describing the gradation to the implementation in a numerical model and its validation by comparing experimental and simulated bending operations is carried out on a DC04 cold-forming steel in order to prove its influence on the springback behavior. It is shown that including graded material properties in simulations does indeed have an impact on the prediction quality of springback and that the information about inhomogeneous properties can be provided by existing characterization methods with a high local resolution like electron backscatter diffraction or X-ray stress analysis. In a further step, it was possible to validate the improvement in numerical accuracy by comparing the prediction of the springback angle from both the existing and the extended model with experimental bending results. Both the initial model as well as the model supplemented with the 3D properties provide a good prediction accuracy in the solution heat treated material state. For the predeformed material, however, the initial numerical model predicts a springback angle of about 13°, which deviates remarkably from the experimentally obtained mean value of about 17°. The extended model delivers a significantly improved accuracy in springback prediction in relation to the initial prediction (deviation of 4°) with a minor deviation of only about 0.8°, which proves the importance of considering the gradation of material properties in thickness direction for an overall higher dimensional accuracy of sheet metal product
Keywords: sheet metal; forming; springback; simulation; microstructural modelling; strain; residual stress; characterization

Improvement of surface integrity of cold forging tools by adaption of tool making process - Andreas, Kolja; Merklein, Marion (Production Engineering, 2014)
Cold forging enables mass production of steel based components. High loads within cold forging presuppose high loadable tool materials. This is why apart from tool steels cemented carbides are mainly used as tool materials. Due to brittleness of these materials, fatigue is one of the major limits of tool life. Tool manufacturing requires a combination of hard machining and subsequent machining steps. For hard machining of complex tool geometries electrical discharge machining (EDM) represents the industrial standard. The thermal influenced surface layer has to be removed by post and fine machining steps. The resulting surface integrity has a major influence on the internal strength of a tool. Correlations between tool manufacturing, surface properties and tool behavior will gain knowledge for an optimized tool production. In this context, scope of the present paper are the investigation and description of the interactions between tool manufacturing and resulting surface properties for tools made of cemented carbide and tool steel. Within the article, the surface properties caused by a conventional process chain consisting of EDM and polishing are quantified. In addition, these results are compared to an adapted process chain with an integrated peening process. The results reveal that the conventional and the adapted process chain lead to similar surface topographies and roughness values. However, the integration of a peening process shifts the residual stress level towards higher compressive stresses. © 2013 German Academic Society for Production Engineering (WGP).
LFT Import::2019-07-29 (1929)
Keywords: Machining; Surface analysis; Surface integrity; Tool

Improvement of the drawing ratio of the anisotropic material behaviour under near plane strain conditions for DP600 characterized in elliptic hydraulic bulge test - Lenzen, Matthias; Merklein, Marion (Institute of Physics Publishing, 2018)
The plane strain condition is one of the most frequent reasons for failure in a deep drawing process. State of the art material models do not consider this strain state in FE simulations. Since there is only the notched tensile test to determine the first principal stress, an improved testing setup is needed to characterize the first and second principal stresses up to high deformations to determine the material behaviour under plane strain conditions. Within this contribution, an innovative testing setup is used, which induces a near plane strain regime in the specimen with an elliptical hydraulic bulge test. Experiments are carried out in rolling and transversal direction for DP600. Based on the experiments, stress and stain based material characteristics are evaluated. For validation of the setup, square cups are deep drawn, which have a plane strain area at the drawing radius which causes cracking under this strain state. Due to the highly directional dependent material behaviour, the drawing ratio can be increased by considering the anisotropic material behaviour by cutting the blank in an optimized position according to the rolling direction.
LFT Import::2019-08-05 (2315)

Improvement of the Formability of Aluminum Extrusion Profiles by a Tailored, Local Short-Term Heat Treatment - Merklein, Marion; Lechner, Michael; Graser, Matthias (Proceedings COMA16, 2016)
LFT Import::2019-08-05 (2156)

Improvement of the Layer Adhesion of Composite Cardiac Patches - Ruther, Florian; Zimmermann, Andrea; Engel, Felix; Boccaccini, Aldo R. (Advanced Engineering Materials, 2019)
The major purpose of cardiac patches is to deliver healthy cells to infarcted tissues. Such cardiac patches must fulfill specific mechanical as well as chemical requirements. Herein, bi-component cardiac patches are investigated with regard to their layer adhesion. Combinations of salt-leached porous poly (glycerol sebacate) (PGS) films with a layer of electrospun-gelatin fibers are produced. Gelatin fibers are fabricated by solution electrospinning using 20 wt% gelatin in 98 v% formic acid. Fibers are attached to PGS films either via direct electrospinning on top of the film or via combining as spun fiber mats with PGS using gelatin as glue. Scanning electron microscopy (SEM) images show that fiber mats adapt to the rough surface of the porous PGS film. In contrast, fibers spun directly onto films show poor adhesion and only a few fibers are attached to the PGS substrate. Fourier transform infrared (FTIR) analysis, contact-angle measurements, and pull-off adhesion tests of the bi-component patches confirm these results. Modified pull-off adhesion tests of the two layers show that combining as spun gelatin fiber mats with porous PGS substrates by gluing leads to excellent material adhesion before and after incubation for up to 14 days.
CRIS-Team Scopus Importer:2019-11-19
Keywords: bi-layer adhesions; cardiac patches; electrospinning; gelatin; porous poly (glycerol sebacate)

Improvement of Tool Life and Working Accuracy in Cold Forging by Numerical Process Simulation - Arbak, Murat; Völkl, Ralf; Engel, Ulf (Proceedings of the 8th International Conference on Technology of Plasticity (ICTP), 2005)
LFT Import::2019-08-05 (1205)

Improvement of Tool Life in Cold Forging by FE-Simulation with the Consideration of Stochastical Process Characteristics - Völkl, Ralf; Engel, Ulf (Finite Elements in Analysis and Design, 2003)
LFT Import::2019-07-15 (939)

Improvement of Tool Life in cold Forging by Locally Optimized Surfaces - Wagner, Kay; Putz, Alexander; Engel, Ulf (Journal of Materials Processing Technology, 2006)
Cold forging tools are exposed to extremely high loads. Depending on the most critical combination of the dominant factors characterizing the load which can be different even within the same tool, different damaging mechanisms will be initiated at least one of which is finally limiting tool life by either wear or fatigue. Since these failure mechanisms are mostly initiated on the tool surface the adjustment of surface properties to the local effective load combination might improve tool performance and increase tool life. In this paper, three different methods are being investigated: hard roller burnishing, laser beam treating and surface texturing. The determination of the tool load is a precondition for the selection of the appropriate surface treatment method. Thus, to find out which of the three methods can be used for tool surfaces in selected case studies, process simulation by finite-element-analysis becomes mandatory. Accordingly, FEA is used to select the optimum surface treatment which is then applied and tested in industrial applications. © 2006 Elsevier B.V. All rights reserved.
LFT Import::2019-07-16 (1261)
Keywords: Cold forging; Finite-element-analysis; Hard roller burnishing; Laser beam treating; Surface texturing; Surface treatment; Tool life

Improvements in CAD/CAM through modelling the weld thermal cycle - Kirk, C.S.; Balogh, A.; Komlodi, Attila; Mileman, A.R. (Proceedings of microCAD, International Computer Science Conference, 1998)
LFT Import::2019-08-05 (1630)

Improvements in the Aluminium Welding Process through FE-Modelling - Komlodi, Attila; Otto, Andreas; Geiger, Manfred (Sheet Metal 2003, Proceedings of the 9th International Conference on Sheet Metal, 2003)
LFT Import::2019-08-05 (968)

Improving Laser Ablation by Controlled Laser Beam Parameters. - Kauf, Michael; Hutfless, Joachim; Geiger, Manfred (Proc. of the EuroLaser Academy, 1995)
LFT Import::2019-08-05 (570)

Improving the local formability of a AA7075 aluminum alloy by laser-induced modification of the alloying concept - Zieroth, Henrik; Stephan, Marcel; Schmidt, Michael; Merklein, Marion (MATEC Web of Conferences, 2025)
With expanding applications in aerospace, automotive, and advanced manufacturing, the need for adaptable materials with tailored mechanical properties is pressing. This study presents a novel approach for selective element adaptation, applied to AA7075 - a high-strength aluminum alloy valued for its exceptional strength but limited by low ductility. Through controlled vaporization of zinc (Zn) and magnesium (Mg), this method enables targeted adjustments in local properties to enhance formability. To evaluate process stability, a comparison was conducted between standard linear vaporization and an advanced double-beam technique, leveraging an optical system that splits and aligns the collimated laser beam for enhanced control. Formability is assessed via 3-point bending tests at varying angles, contrasting vaporized AA7075 with both an exclusively vaporized variant and a silicon-alloyed version approximating the ductility profile of 6xxx alloys. Findings indicate that element-adapted blanks, entitled as Tailored Alloyed Blanks (TAB), achieve significant improvements in localized formability and process stability, establishing a promising technique for the development of adaptable, high-strength materials suited to complex component designs and diverse industrial application
Keywords: Tailor Alloyed Blanks (TAB); laser beam welding; element evaporation; aluminum alloys

Increased Sustainability in Fastener Production with the Example of Self-Piercing Rivets - Uhe, Benedikt; Kuball, Clara-Maria; Merklein, Marion; Meschut, Gerson (Journal of Manufacturing and Materials Processing, 2023)

Increased Tool Life in Cold Forging with Micro Textured Tool Surface - Popp, Uwe; Engel, Ulf; Geiger, Manfred (ICEM 2003, Proceedings of the International Workshop on Environmentally Conscious Manufacturing, 2003)
LFT Import::2019-08-05 (993)

Increase of Efficiency for the XeCl excimer laser ablation of ceramics - Geiger, Manfred; Becker, Wolfgang; Rebhan, Thomas; Hutfless, Joachim; Lutz, Norbert (Applied Surface Science, 1996)
LFT Import::2019-07-15 (637)

Increasing the Adhesive Wear Resistance of Hot Stamping Tools By Modifiying the Surfaces - Neubauer, Franziska; Reil, T.; Hofmann, K.; Merklein, Marion (Key Engineering Material, 767, 2018)
LFT Import::2019-08-05 (2320)

Increasing Tool Life in Cold Forging by Laser Micro Texturing the Tool Surface - Popp, Uwe; Engel, Ulf; Geiger, Manfred (Proceedings of the 3rd International Conference THE Coatings in Manufacturing Engineering, 2002)
LFT Import::2019-08-05 (1683)

Induction heat treatment of sheet-bulk metal-formed parts assisted by water-air spray cooling - Besserer, Hans-Bernward; Dalinger, Andrej; Rodman, Dmytro; Nuernberger, Florian; Hildenbrand, Philipp; Merklein, Marion; Maier, Hans Juergen (Steel Research International, 2016)
In order to produce components with massive secondary functional elements from sheet metal bulk forming operations, termed sheet-bulk metal forming, can be applied. Owing to high, three-dimensional stress and strain states present during sheet-bulk metal forming, ductile damage occurs in the form of micro-voids. Depending on the material flow properties, tensile residual stresses can also be present in the components' formed functional elements. During service, the components are subjected to cyclic loading via these functional elements, and tensile residual stresses exert an unfavorable influence on crack initiation and crack growth, and therefore on the fatigue life. Following the forming process, temperature and microstructurally related compressive residual stresses can be induced by local heat treating of the surface. These residual stresses can counteract potential crack initiation on the surface or in the subsurface regions. In the present study, the adjustability of the residual stress state is investigated using a workpiece manufactured by orbital cold-forming, which possesses an accumulation of material in its edge region. Based on residual stress measurements in the workpiece's edge region using x-ray diffractometry, it is possible to verify the compressive residual stresses adjusted by varying the cooling conditions.
LFT Import::2019-07-29 (2150)
Keywords: DP600; induction heat treatment; orbital forming; residual stress; water–air spray cooling

Industrial Ceramics in Cold Forging: Increasing Dimensional Accuracy and Surface Quality - Arbak, Murat; Putz, Alexander; Engel, Ulf; Geiger, Manfred (Proceedings of the 4th JSTP International Seminar on Precision Forging, Nara, Japan, 2006)
LFT Import::2019-08-05 (1258)

Infiltration as post-processing of laser sintered metal parts - Dück, J.; Niebling, Frank; Neeße, T.; Otto, Andreas (Powder Technology, 2004)
Laser sintering of metal parts is an additive production method applied in the field of rapid prototyping and rapid tooling. Direct metal laser sintering (DMLS) is a variant of the laser sintering processes. Metal powder is locally molten in this process and parts are built from layers. A fast laser sintering process, which is economically favourable, results in porous metal parts. For a technical application as e.g. the production of injection moulds for plastic parts, the surface has to be dense at a defined quality. A post-processing via infiltration is a possible solution for creating such surfaces. This paper describes the results of a study of the infiltration process: A model for describing the infiltration behaviour has been developed and validated through experiments. © 2004 Elsevier B.V. All rights reserved.
LFT Import::2019-07-16 (1059)
Keywords: Infiltration; Laser sintering; Rapid prototyping

Influence factors of three-roll-push-bending - Plettke, Raoul; Vipavc, Daniel; Vatter, Peter (Proc. 1st Int. Tube and Profile Bending Conf., 2011)
LFT Import::2019-08-05 (1760)

Influence of a bending operation on the bonding strength for hybrid parts made of Ti-6Al-4V - Papke, Thomas; Dubjella, Patrick; Butzhammer, Lorenz; Huber, Florian; Petrunenko, Oleksandra; Klose, Dominik; Schmidt, Michael; Merklein, Marion (Procedia CIRP, 2018)

Influence of a drawbead passage in deep drawing processes on surface values and the tribological system - Schmid, Harald; Merklein, Marion (International Deep-Drawing Research Group (IDDRG 2020), 2020)

Influence of a local laser heat treatment on the bending properties of aluminium extrusion profiles - Graser, Matthias; Pflaum, Nico; Merklein, Marion (Procedia CIRP, 2018)
Driven by ecological and economical demands, lightweight design and in this context, the substitution of steel by aluminium has become a major trend in the automotive industry. However, design possibilities are limited by the low formability of aluminium alloys. One approach to overcome these limitations is the usage of tailor heat treated semi-finished products. By a local short-term heat treatment, distinct areas are softened, which can be used to improve the material flow into critical forming zones. Within this work, the influence of local short-term heat treatment on the formability of aluminium extrusion profiles is analysed by experimental bending tests. Aims are the enhancement of maximum reachable bending angles as well as the reduction of cross section deformations. Therefore, different heat treatment layouts are applied by laser irradiation. Finally, the bending results are evaluated and promising heat treatment strategies are derived.
LFT Import::2019-07-29 (2336)
Keywords: Aluminium; Bending; Extrusion profiles; Heat treatment

Influence of a local short-term heat treatment on the formability of orbital formed functional components - Hetzel, Andreas; Merklein, Marion; Lechner, Michael (Procedia Manufacturing, 2021)
Conventional processes like shearing dispose a lack in efficiency and formability to manufacture functional components with a high geometric variety. A possibility to allow the efficient and sustainable manufacturing is the application of innovative forming operations like orbital forming. Thus, a strain-hardened component with a load-adapted thickness profile can be manufactured in a single-stage process. Thereby, the control of the material flow could be identified as major challenge due to the three-dimensional stress and strain state. In order to reduce the parts weight and simultaneously guarantee the same level of performance, conventional steel is substituted by lightweight materials such as precipitation hardenable aluminum alloys. However, new challenges arise due to the reduced formability of aluminum compared to conventional steel. In recent research, the potential of a short-term heat treatment to enlarge the formability could be shown. The presented process locally reduces the materials strength, thus allowing a control of the material flow by the interaction between softened areas and areas, which offer the initial conditions. In this contribution, the influence on the formability of orbital formed components manufactured out of the precipitation hardenable aluminum alloy EN AW 6016 by a local short-term heat treatment is investigated. Different geometry-based heat treatment layouts are applied in order to maximize the thickening on different radial positions. The potential to enhance the formability is evaluated by comparing geometrical and mechanical properties of the components manufactured in the conventional process route and with a previous heat treatment. The analysis of radial cross-sections and the hardness distribution reveals the positive influence of the heat treatment but also points out the geometrical dependency of the effect due to the characteristic material flow in orbital forming.<br
CRIS-Team Scopus Importer:2021-11-05
Keywords: Sheet-Bulk Metal Forming; Orbital Forming; Local Short-term Heat Treatment; EN AW 6016; Material Flow Control; Lightweight Design

Influence of an optical strain rate controlled tensile testing method on mechanical properties of sheet metals - Naumann, David; Merklein, Marion (Material Forming The 27th International ESAFORM Conference -On Material Forming, 2024)
Abstract. Precise material characterization is a key factor not only for representative finite-element-analysis (FEA) in production technology, but also for product development in general. Hereby, the tensile test is of particular importance, as it can be used to determine the most relevant material parameters. These are used to ensure a better process and tool design but therefore material behavior has to be determined to a high level of precision [1]. Especially in the field of metal forming, strain rate sensitive material properties like work hardening, yield point or tensile strength need to be measured at constant strain rate to provide coherent data for material models in numerical forming simulations [2]. Current testing procedures control the strain rate with a feedback control, in which various measuring systems can be used. From this comes the necessity to investigate the influence of a strain rate controlled tensile testing procedure compared to a conventional crosshead-displacement controlled one. Thus, in the scope of this study, an optical strain rate controlled (OSRC) tensile test procedure with a digital image correlation (DIC) system, and a universal testing machine (UTM) was developed. The resulting mechanical properties and the evolution of the strain rate during the test of the steel DP600 (CR330Y590T-DH) and DC05 (CR4) were analyzed at a nominal strain rate of 0.4 %/s. In addition, the results obtained from displacement strain rate controlled (DSRC) tensile tests were compared. The results demonstrate that OSRC testing method enables the measurement of mechanical material properties at a higher level of precision in terms of constant strain rate compared to DSRC procedure.<br

Influence of a short-term heat treatment on the formability and ageing characteristics of aluminum profiles - Merklein, Marion; Lechner, Michael; Graser, Matthias (Lasers in Manufacturing Conference, 2015)
LFT Import::2019-08-05 (2113)

Influence of Combined Hard and Fine Machining on the Surface Properties of Cemented Carbides - Andreas, Kolja; Merklein, Marion; Engel, Ulf (Tribology in Industry, 2012)
As a result of recent developments in cold forging cemented carbides are increasingly used as tool materials. Due to their high hardness only electrical discharge machining (EDM) and grinding are suitable for tool machining. The structure of tool surface has significant influence on dominating failure mechanisms wear and fatigue. For improvement of tribological conditions the surface is polished in a finale processing step. The result of hard and fine machining is a specific combination of coarse and fine structure which is determined by processing parameters. The different surface structures lead to a particular tool behavior in forming process. This paper aims to show the influence of combined hard and fine machining on the surface properties of cemented carbides. © 2012 Published by Faculty of Engineering.
LFT Import::2019-07-29 (1859)
Keywords: Cemented carbide; Cold forging; Surface machining

Influence of component design on extrusion processes in sheet-bulk metal forming - Pilz, Florian; Merklein, Marion (International Journal of Material Forming, 2019)
Nowadays, the functional integration of workpieces challenges existing forming processes. The combination of established forming processes – like sheet metal and bulk forming – offers the possibility to counter this issue. The application of bulk forming operations on sheet metal semi-finished products, also called sheet-bulk metal forming (SBMF), is an innovative approach. The potential of SBMF cannot be fully exploited, as there are no recommendations in terms of workpiece design and layout influence on the process result. Therefore, this paper focuses on the analysis of semi-finished products and component design parameters on resulting part and process properties in two extrusion processes in SBMF. The investigation is based on a combined numerical and experimental approach. It is shown that the investigated design parameters, in addition to the achievable dimensional accuracy, substantially influence the occurring tool loads as well as the required process forces.
CRIS-Team Scopus Importer:2019-11-29
Keywords: Component design; Extrusion; Sheet forming; Sheet-bulk metal forming; Simulation

Influence of Cutting Processes on Edge Cracking Sensitivity of Bright Finishing Alloys - Merklein, Marion; Gnibl, Tobias; Tsoupis, Ioannis; Friedrichsen, Martin; Beck, Johannes (Key Engineering Materials, 2016)
LFT Import::2019-07-29 (2189)
Keywords: Aluminum; Cutting Edge; Sheet Metal Forming

Influence of dry ice blasting process properties on surface roughness and residual stresses of machined and additive manufactured workpieces - Amon, Sven; Jobst, Andreas; Merklein, Marion; Hanenkamp, Nico (Procedia CIRP, 2022)
Dry ice blasting has shown the potential to remove metallic burrs after machining processes and support structures after additive manufacturing. During blasting, process parameters need to be chosen depending on the material and the geometric properties of the burr. However, dry ice blasting affects the local material properties on a micro level and improper blasting parameters may lead to changes in the part surface. In this article, correlations and interactions between dry ice blasting parameters and resulting specimen roughness and residual stresses are identified for machined and additive manufactured metallic materials.<br
Keywords: dry ice blasting; metallic edge zone; deburring; post-processing; residual stresses

Influence of Grinding on the Surface Properties of Cemented Carbides - Andreas, Kolja; Engel, Ulf; Merklein, Marion (Key Engineering Materials, 2012)
The increased demand for manifold industrial goods requires superior manufacturing techniques. In the field of steel products, cold forging has gained importance for the last sixty years. Within cold forging the tool takes a key role as it determines both accuracy and efficiency of forming process. For forming processes with high demands regarding wear resistance WC-Co cemented carbides are increasingly used as tool materials. The manufacturing process of the tool requires a combination of hard and fine machining. In order to reduce the effort of subsequent fine machining process, surfaces with low roughness are preferred. As grinding leads to high surface qualities, it is a common method in tool machining. Grinding is accompanied by compressive residual stresses in the surface which have a positive influence on the tool life. The absolute value of residual stresses is determined by the machining parameters. The present study investigates the influence of feed and in-feed on the topography and the near surface residual stresses. While the surface roughness is correlated with both parameters, the feed has a major influence on the residual stresses in the surface of cemented carbides.© (2012) Trans Tech Publications.
LFT Import::2019-07-29 (1780)
Keywords: Cemented Carbides; Grinding; Residual Stresses

Influence of Hot Isostatical Pressing on the Mechnical Behaviour of CVD-coated Hardmetals - Tolazzi, Massimo; Kursawe, S.; Sockel, H.G. (AMST 02: Advanced Manufacturing Systems and Technology: Proceedings of the 6th International Conference, 2002)
LFT Import::2019-08-05 (1674)

Influence of laser generated micro textured coated tool surfaces on dry deep drawing processes - Tenner, Jennifer; Häfner, Tom; Rothammer, Benedict; Krachenfels, Kim; Zhao, Rong; Schmidt, Michael; Tremmel, Stephan; Merklein, Marion (Dry Metal Forming Open Access Journal, 2018)
The idea of sustainability and resource conservation promotes the development of energy-efficient and low-emission production processes. A lubricant-free sheet metal forming process is considered as one of these environmentally friendly production technologies. Metal forming processes without conventional lubricants shorten process steps and reduce additional costs, such as removal of residual lubrication from the workpiece after forming. In order to realize such a dry forming process and effectively control the material flow, amorphous carbon coatings were applied to the tool surfaces and a brushing process was carried out as a surface finishing process for roughness adjustment. Laser generated micro features on the surface should make an effective contribution to local friction adaptation. The transferability of strip drawing test to strip bending rotation test was successfully demonstrated by dry and oiled blank reference tests. The first modification of the tool sided surface was achieved by applying ta-C and a-C:H layers. The influence of the coatings on the tribological behaviour was determined in strip drawing tests for DC04 and AA5182. Additional friction adaptation is made possible by the fine and flexible laser based micro texturing of the coated tool surface. Experiments were carried out with different coverage and depth of the laser generated features in order to analyze the tribological influence. Flat and deep features with a degree of coverage of 20 %, 35 % and 50 % are considered in order to analyze the factors influencing their tribological behavior. Compared to ta-C coated references, it can be seen that micro features on the ta-C coated tool surface causes a friction reduction for DC04, independent of the features depth. However, deep laser generated features in particular lead to an increase in friction for AA5182, so that this could potentially lead to a selective local increase in friction in the flange area. For the transferability of the tribological system from the flat application case to a curved tool surface, the basics for laser based texturing of cylinder surfaces are illustrated. The limits of the holographic beam shaping technology used for this are demonstrated.
Keywords: Dry Deep Drawing; Tribology; Carbon Based Coatings; Laser Based Texturing

Influence of laser-produced microstructures on the tribological behaviour of ceramics - Geiger, Manfred; Roth, Stephan; Becker, Wolfgang (Surface & Coatings Technology, 1998)
LFT Import::2019-07-16 (1594)
Keywords: Ceramics; Excimer laser; Microstructuring; Tribology

Influence of machining process on residual stresses in the surface of cemented carbides - Merklein, Marion; Andreas, Kolja; Engel, Ulf (Procedia Engineering, 2011)
LFT Import::2019-07-29 (1766)
Keywords: Cemented carbide; Residual stress; Tool

Influence of manufacturing process on the fatigue strength of gears - Reiß, Andrea; Engel, Ulf (Advanced Materials Research, 2014)
With cold forging processes it is possible to produce parts characterized by high strength, high dimensional accuracy and high surface quality. In order to optimize the forming process and to be able to use the advantages of cold forging specifically and combined, it is necessary to find correlations between manufacturing parameters on the one side, strength and other properties like hardness distribution and surface quality of the component on the other side. The research work covered in this paper focuses on the correlation of the components properties influenced by its manufacturing history and their fatigue strength. The used component is a gear produced by a lateral cold forging process. For the investigations an experimental setup has been designed. The aim for the design of the setup is to reproduce the real contact condition for the contact of two gears. To obtain different component properties the production process of the gear was varied by producing the parts by a milling operation. First of all, the components’ properties, for example hardness distribution, remaining residual stresses, orientation of fibers and surface quality, were determined. The components’ fatigue behavior was determined using a high frequency pulsator and evaluated in terms of finite life fatigue strength and fatigue endurance limit. These examinations were used to produce Woehler curves for the differently manufactured components with a certain statistical data analysis method.
LFT Import::2019-07-29 (2042)
Keywords: Cold forming; Fatigue; Gear

Influence of Material Delivery Condition on Residual Stresses and Part Properties During Forward Rod Extrusion - Jobst, Andreas; Merklein, Marion (13th International Conference on the Technology of Plasticity, 2021)
During the manufacturing of semi-finished products, the material is subjected to various forming steps to achieve the final geometry. In order to reduce the work hardening introduced and to ensure a good formability, it is annealed before component manufacturing. Forming technologies like forward rod extrusion are well-established methods for the efficient production of resilient components. In this process, however, an inhomogeneous pre-strengthening of the material influences the stress distribution during forming and therefore the mechanical properties and the residual stresses in the component. Since they affect the parts’ operating behaviour, knowledge of the influence of the delivery condition of the material is necessary. The aim of this paper is to derive dependencies between material properties and the resulting residual stresses and work hardening in the component. Due to the increasing application, ferritic stainless steel X6Cr17 in the skin passed (+LC) and soft annealed (+A) states are used. Residual stresses, microstructure, and microhardness distribution of both material states are compared regarding the rods and extruded parts. The effects of the delivery condition are evaluated by comparing process and component properties.
Keywords: Forward extrusion; Material condition; Stainless steel; Residual stress; Work hardening

Influence of material in sheet-bulk metal forming from coil - Leicht, Miriam; Merklein, Marion (Production Engineering, 2024)
Sheet-bulk metal forming (SBMF) represents an innovative approach for the efficient manufacturing of functional integrated parts from sheet metal by applying bulk forming processes to sheet metal. It combines the advantages of part weight optimization and process chain shortening. In view of the increasing demand for functionally integrated components, the forming from coil offers an economical possibility to produce high output rates. Nevertheless, an underfilling of functional elements as well as an asymmetric part forming are current challenges. In order to apply SBMF from coil in industrial contexts, it is necessary to understand the causes of these process limits and to develop measures for improving the forming of functional elements and thereby push existing forming limits. In this paper, both a lateral and a backward extrusion process from coil for the forming of internal and external geared SBMF parts are investigated to develop a fundamental process understanding. In a combined numerical-experimental approach, the influence of the flow behavior of different materials as well as the impact of the main material flow direction of the process on the dimensional part accuracy is analyzed. This enables the evaluation of fundamental material-related dependencies and influences regarding the geometrical part accuracy, the mechanical component properties and the tool load for forming of the conventional deep-drawing steel DC04 (t0 = 2 mm), a high-strength steel material (HC260LA) and an aluminum alloy (AA6082 T6). Based on these findings, measures for material flow control are identified and investigated to counteract the challenges of SBMF from coil. These findings permit the identification of potential transferability of the identified cause-effect mechanisms to different processes, component geometries and materials. Thereby, in particular, an increase in coil width as well as lower a strain hardening behavior of the material offers the possibility to improve the geometrical accuracy of the components.
CRIS-Team Scopus Importer:2024-08-16
Keywords: Cold Forming; Extrusion; Sheet-bulk metal forming

Influence of Materials and Its Conditions on Pin-Extrusion from Sheet Metal - Kraus, Martin; Merklein, Marion (Lecture Notes in Mechanical Engineering, 2024)
Pin structures extruded from the sheet metal plane have numerous industrial applications. For instance, they can be used in bulk microforming to solve handling difficulties or in joining technology to connect dissimilar materials. Due to the absence of material flow restrictions in the direction of the sheet metal plane, pin extrusion is affected by numerous process-, workpiece- and tool-related parameters, which have a huge impact on the material utilization and the obtainable pin geometry. Within the scope of this study, a combined numerical-experimental research approach is used to analyze the influence of the material and its condition on the achievable pin height and the occurrence of the mostly undesired funnel formation at high punch penetration depths. For this purpose, elastic-ideal plastic and elastic-real hardening model materials are first investigated numerically, which are subsequently validated and verified in experiments by using the materials Cu-OFE, AA6016, DC04 on a laboratory scale. Based on the results, recommendations for the material selection and its properties are derived in order to maximize the material utilization.
Created from Fastlane, Scopus look-up
Keywords: extrusion; material flow; pin-extrusion; sheet metal

Influence of Media on Process Stability in Sheet Metal Hydroforming - Geiger, Manfred; Merklein, Marion; Blankl, Andreas (International Journal of Materials & Product Technology, 2008)
The difference between sheet metal hydroforming and deep drawing is elementary: one half of the tool is substituted by hydraulic pressure. In order to guarantee an optimised forming result a tight cavity in the tool has to be created, since as soon as a leakage occurs, the forming pressure decreases rapidly and the forming operation is interrupted. The separation plane of the tool is the critical area for an occurring leakage because here a metallic sealing is often realised. Therefore, the objective of this paper is to present theoretical consideration on the leakage problematic in hydroforming. For illustration of the problem an existing process chain is presented in the beginning of this paper. Subsequently theoretical considerations are made. In the end a new strategy for defusing the leakage problem by changing the hydroforming media is presented in the outlook. Copyright © 2008 Inderscience Enterprises Ltd.
LFT Import::2019-07-29 (1505)
Keywords: Hydroforming; Process stability; Sheet metal

Influence of Metal Flank Hardness of Machined and Cold Forged Gears on Wear within a Metal-Polyamide Gear Pair and Targeted Process Adaptation - Rohrmoser, Andreas; Merklein, Marion (Journal of Materials Engineering and Performance, 2022)
Metal-polyamide gear pairs provide advantages but their application is limited due to wear. The properties of the metallic gearing significantly affect the wear behavior. However, the influence of varying metallic materials as well as flank hardness is not known. Within this contribution, the occurring wear mechanisms when applying steel, brass and aluminum with varying hardness resulting from manufacturing by machining and cold forging were identified. Depending on the hardness of the metallic tooth flank, the release of metallic particles (3-body abrasion) or surface roughening (2-body abrasion) results. The formation of a wear-reducing transfer film is only possible with sufficient strength of the metallic tooth flank and tribological compatibility. Maximum wear occurs at a metal hardness of about 120 HV due to 3-body abrasion with high abrasive effect of the metallic particles. The adaptation of the cold forging process enables a local increase in the plastic strain of the tooth flank by 84% resulting in an elevated tooth flank hardness (+ 53%) for aluminum and significantly reduced wear. Furthermore, the formation of a wear-reducing transfer film results. Aluminum pinions produced in the adapted cold forging process achieve performance level of steel within the investigated load case.
CRIS-Team WoS Importer:2022-09-09

Influence of metal gear tooth geometry on load and wear within metal-polymer gear pairs - Rohrmoser, Andreas; Bode, Christoph; Schleich, Benjamin; Hagenah, Hinnerk; Wartzack, Sandro; Merklein, Marion (Applied Sciences, 2022)
Gear pairs made of the material pairing metal-polymer provide advantages, such as a reduced weight, beneficial damping properties and the possibility to be operated in dry running conditions. However, the service life of the pairing is limited due to wear. The properties of the metallic gearing have a significant influence on the wear behavior of the material pairing. From previous investigations, the influence of the surface topography and the flank hardness of the metal pinion is known. With regard to resource saving and efficient manufacturing of the metal pinion, cold forging offers benefits. Through cold forging, metallic gears for the material pairing can be produced ready-to-use in a process suitable for serial production. In order to enable manufacturing by extrusion, the application of gear radii is necessary. The gear radii significantly affect the extrusion process and the achievable gear properties. However, the influence of gear radii on wear within the metal-polymer material pairing has not yet been investigated. Within this contribution, the influence of the gear radii on the contact behavior as well as the resulting local load and wear of the tooth flank is determined. For this purpose, wear tests with aluminum (AlMgSi1) and steel (16MnCr5) gears with different gear radii within the pairing with polyamide (PA66) gears were performed. It has been shown that the local wear of the tooth flank can be attributed to the local load and that adjusted gear radii lead to a varying load and wear of the metal and polymer gears. Based on the findings, functional relationships regarding the choice of gear radii and the wear behavior are derived which can be applied in the design of cold forged gears.
Created from Fastlane, Scopus look-up
Keywords: Gear; Metal; Polymer; Tooth contact; Tooth geometry; Wear

Influence of metal inserts with microformed edges on subsequent injection assembly moulding for media tight electronic systems - Frey, Philipp; Heinle, Martina; Drummer, Dietmar; Merklein, Marion (4th International Conference on New Forming Technology, ICNFT 2015, 2015)

Influence of microstructure on the mechanical properties and the forming behaviour of very thin metal foils - Diehl, Alexander; Engel, Ulf; Geiger, Manfred (International Journal of Advanced Manufacturing Technology, 2010)
The demand for accurate process design of microforming processes is increasing steadily due to ongoing miniaturisation. Occurring size effects, however, prevent the transfer of existing know-how of standard sheet forming processes with conventional dimensions like blanking, bending and deep drawing on microforming processes. These size effects are either generally valid for all microforming processes, as the influence of the share of surface grains are process-specific, like the influence of large strain gradients as they appear, e.g. in bending processes. A decisive parameter for the occurrence of size effects is the ratio of material mean grain size to foil thickness. For a simulation-based description of microforming processes, the implementation of size-dependent material behaviour in finite element (FE) simulation is essential. Hence, a reliable determination of size-dependent mechanical properties as input data for FE simulation is needed to provide a broad fundamental database for a future theoretical description of microforming processes. In the present paper, the influence of the material microstructure on the mechanical properties of metal foils with thicknesses ranging from 25 to 500 μm is discussed based on tensile tests, bulge tests and fundamental bending experiments. Challenges resulting from the small thickness of the metal foils are pointed out, and future demands regarding determination of material characteristics of thin metal foils are presented. © 2008 Springer-Verlag London Limited.
LFT Import::2019-07-29 (1536)
Keywords: Bending; Hydraulic bulge test; Mechanical properties; Metal foils; Pneumatic bulge test

Influence of predeformation on the formability of aluminium alloys - Merklein, Marion; Beccari, S. (Proceedings of the 8th International Conference on Technology of Plasticity (ICTP), 09.-13.10., Verona, Italy, 2005)
LFT Import::2019-08-05 (1221)

Influence of Pre-forming on the Forming Limit Diagram - Tolazzi, Massimo; Merklein, Marion (Key Engineering Materials, 2007)
LFT Import::2019-07-16 (1468)

Influence of Pre-forming on the Forming Limit Diagram of Aluminium and Steel Sheets - Tolazzi, Massimo; Merklein, Marion (Sheet Metal 2007, Proceedings of the 12th International Conference on Sheet Metal; Advanced Materials Research, 2007)
This paper presents a method for the experimental determination of forming limit diagrams under non linear strain paths. The method consists in pre-forming the sheets under two different strain conditions: uniaxial and biaxial, and then stretching the samples, cut out of the preformed sheets, using a Nakajima testing setup. The optical deformation measurement system used for the process analysis (ARAMIS, Company GOM) allows to record and to analyze the strain distribution very precisely with respect to both time and space. As a reference also the FLDs of the investigated grades (the deep drawing steel DC04, the dual phase steel DP450 and the aluminum alloy AA5754) in as-received conditions were determined. The results show as expected an influence of the pre-forming conditions on the forming limit of the materials, with an increased formability in the case of biaxial stretching after uniaxial pre-forming and a reduced formability for uniaxial load after biaxial stretching if compared to the case of linear strain paths. These effects can be observed for all the investigated materials and can be also described in terms of a shifting of the FLD, which is related to the art and magnitude of the pre-deformation.
LFT Import::2019-08-05 (1387)
Keywords: Forming limit diagram; Sheet metal forming; Strain path

Influence of Pre-Strain and Simulated Paint-Bake on Mechanical Properties of High Strength Aluminium Alloy AA7020 - Merklein, Marion; Degner, Julia (Applied Mechanics and Materials, 2015)
LFT Import::2019-07-29 (2122)

Influence of Pre-straining and Heat Treatment on the Yield Surface of Precipitation Hardenable Aluminum Alloys - Lechner, Michael; Johannes, Maren; Kuppert, Andreas; Merklein, Marion (Physics Procedia, 2014)
LFT Import::2019-07-29 (2045)
Keywords: Aluminum; Intermediate heat treatment; Yield surface

Influence of Process and Material Parameters on Ablation Phenomena and Mechanical Properties of Ceramics and Composites for Excimer Laser Treatment - Geiger, Manfred; Lutz, Norbert; Rebhan, Thomas; Goller, M. (Laser Treatment of Materials, Oberursel : DGM Informationsgesellschaft, 1992)
LFT Import::2019-08-05 (477)

Influence of Process Errors on the Tool Load in Microblanking of Thin Metal Foils with Silicon Punches - Hildering, Sven; Engel, Ulf; Merklein, Marion (9th International Conference on MicroManufacturing (ICOMM 2014), 2014)
Influence of Process Errors on the Tool Load in Microblanking of Thin Metal Foils with Silicon Punches.
LFT Import::2019-07-29 (2011)

Influence of production process-induced surface topologies at varying roughness depths on the tribological properties of polyamide steel contact - Schubert, Dominik; Rohrmoser, Andreas; Herzog, Christoph; Wolf, Michael; Hagenah, Hinnerk; Merklein, Marion; Drummer, Dietmar (Journal of Polymer Engineering, 2023)
Friction and wear in a tribological system are directly dependent on the surface structure and roughness of the friction partners involved. In this article, a clear interaction between surface topologies and their roughness depth was identified for the material pairing polyamide 66 - steel. The typical correlation between roughness and wear, initially decreasing and increasing after a wear minimizing roughness, was found for all surface topologies, albeit at different levels. The effect of the surface topology is negligible at low roughness (S z < 2.0 μm) with adhesive wear processes determining the wear behaviour. At higher roughness depths (S z > 2.0 μm), the ability of the surface topology to form a stable transfer film determines the tribological behaviour by limiting the effect of abrasive wear processes. A stable transfer film is formed with sufficient roughness and undercuts in the direction of motion, which can be characterised by the average roughness depth, R z , in the direction of motion. Based on these empirical results, an explanatory model for the observed behaviour is presented.
Created from Fastlane, Scopus look-up
Keywords: polymer metal contact; surface structure; transfer film; tribology; wear

Influence of short-term heat treatment on the microstructure and mechanical properties of EN AW 6060 T4 extrusion profiles - Part A - Fröck, H.; Graser, Matthias; Reich, M.; Lechner, Michael; Merklein, Marion; Keßler, O. (Production Engineering, 2016)
LFT Import::2019-08-07 (2180)

Influence of short-term heat treatment on the microstructure and mechanical properties of EN AW‑6060 T4 extrusion profiles – Part B - Graser, Matthias; Fröck, H.; Lechner, Michael; Reich, M.; Keßler, O.; Merklein, Marion (Production Engineering, 2016)
LFT Import::2019-07-29 (2179)

Influence of specimen geometry and strain rate on elongation in tensile testing of packaging steel - Knieps, Fabian; Köhl, Manuel; Merklein, Marion (ESAFORM 2021 - 24th International Conference on Material Forming, 2021)
Packaging steel is characterized by low thickness (0.1 mm - 0.5 mm) and ferritic microstructure resulting from low carbon contents. In combination with continuous annealing processes and temper rolling, this results in only little elongation observed in tensile tests. However, as in real forming processes much higher deformation occurs, it is important to receive true stress-true strain data up to a highest possible level e.g. to characterize material for finite element analysis. Therefore, tensile tests with three different measuring lengths (80 mm, 50 mm, 20 mm) were conducted for the packaging steel TH415. Likewise, the testing speed was reduced to investigate the possibility to receive more elongation under the condition of a constant stress level. The results revealed a significant increase in elongation when using smaller tensile test geometries. As well, the reduction in testing speed leads to much higher elongation while showing only little strain rate influence. While for the 80 mm geometry and standard speed no homogenous forming condition could be reached due to early failure before Lüders strain, this could be improved by using smaller testing specimens and a lower strain rate. Combining the influence of strain rate and geometry a significant increase of more than ten percentage points in elongation was reached.
CRIS-Team Scopus Importer:2023-03-29
Keywords: Material characterization; Packaging steel; Tensile test

Influence of specimen size and sheet thickness on the material behavior of AZ31B under uniaxial tension - Suttner, Sebastian; Merklein, Marion (IOP Conference Series: Materials Science and Engineering, 2016)
Concerning a low specific density, magnesium alloys offer a great potential to reduce the part weight. Due to the conditional formability of magnesium alloys at room temperature, forming processes are mostly realized at elevated temperatures. Within this contribution, uniaxial tensile tests for two different specimen geometries with a gauge length of 50 mm and 2 mm and a cross section of 12.5×1 mm2 and 2×1 mm2 are carried out for the magnesium alloy AZ31B at an elevated temperature of 200 °C. Since the specimen size is reduced, the influence of the sheet thickness needs to be analyzed. The analysis of the sheet thickness results in a change of the determined flow curve above a strain level of 0.1 and a much earlier failure of specimen with an initial sheet thickness of 1.5 mm. The changed material behavior can be explained by a different microstructure, e.g. the influence of the grain size. In summary, a characterization of the magnesium alloy AZ31B at elevated temperatures can be realized with a miniaturized test setup.
LFT Import::2019-07-29 (2212)

Influence of stress relaxation after uniaxial pre-straining on subsequent plastic yielding in the uniaxial tensile test of sheet metal - Suttner, Sebastian; Merklein, Marion (Key Engineering Materials, 2015)
Resource efficiency, design oriented accuracy and lightweight properties are demands on modern sheet metal forming parts in the automotive sector. The use of new materials leads to additional challenges on the numerical design of forming processes. During these forming processes the material undergoes different strain states that cause non-linear strain paths. Since the numerical prediction highly depends on the identified characteristic values of the material, an exact characterisation of the material behaviour is essential. Especially obtuse angles of the stress vector trigger a recovery of the material by returning stress. Besides, a relaxation of the material is investigated during holding a constant strain level. The effect of relaxation lead to an altered material behaviour that appears in a reduction of the beginning of plastic yielding. In addition, a kinematic hardening behaviour as under cyclic loading and load reversal, known as the Bauschinger effect, occurs after the relaxation of the stress and results in a reduced beginning of plastic yielding by loading in the same direction as the introduced pre-strain. Within this research work the effect of relaxation is investigated for two materials, AA5182 and DP600, with an initial sheet thickness of 1.0 mm. These materials are typically used for internal and accordingly functional parts in the automotive sector. The relaxation of the material is analysed with different holding times of a constant pre-strain at different levels of straining. The release of the material is studied by subsequent uniaxial tensile tests after pre-straining with the same load condition. Moreover, the influence of the named effects is shown by comparison of the translation of the yield loci.
LFT Import::2019-07-29 (2093)
Keywords: Metal forming; Modelling; Relaxation

Influence of Stress States on Forming Hybrid Parts with Sheet Metal and Additively Manufactured Element - Hafenecker, Jan; Papke, Thomas; Merklein, Marion (Journal of Materials Engineering and Performance, 2021)
Hybrid parts with additively manufactured elements (AME) combine the advantages of two or more manufacturing processes, e.g., forming and additive manufacturing (AM), and thus offer a solution to the increasing demands of industrial trends such as personalized mass production. Despite their advantageous properties, research in this field still lacks in clear classification and process interactions. Due to the strong influence of the AME on the formability of hybrid parts, the combination of laser-based powder bed fusion (PBF-LB) with subsequent sheet metal forming is examined in this paper. Therefore, cylindrical functional elements are built up on sheet metal and the resulting hybrid components are subsequently formed. Common forming processes such as bending, stretch forming and deep drawing are compared in regard to the different stress states. The results show a reduction in formability for hybrid components compared to conventional sheet metal materials. Reasons found are geometrical properties, gradients of mechanical properties and induced stresses. Consequently, requirements for the additive manufacturing process regarding a subsequent forming process are outlined. Namely, the gradient of mechanical properties should be smoothened, residual stresses kept low and the design of AMEs should avoid stress concentration.<br
Keywords: additive manufacturing; hybrid material; modelling and simulation; sheet metal formability; titanium

Influence of surface integrity on the tribological performance of cold forging tools - Andreas, Kolja; Merklein, Marion (Procedia CIRP, 2014)
LFT Import::2019-07-29 (1946)
Keywords: Cold forming; Finishing; Surface integrity; Tribology

Influence of tailored blanks on forming of cold forged functional elements in a sheet bulk metal forming process - Gröbel, Daniel; Hildenbrand, Philipp; Engel, Ulf; Merklein, Marion (Proceedings METEC & 2nd ESTAT, 2015)
LFT Import::2019-08-05 (2080)

Influence of Tailored Surfaces on the Surface Properties of Sheet-Bulk Metal Formed Parts - Wild, Thomas; Merklein, Marion (Proceedings of the Steel in Cars and Trucks (SCT), 2022)
In order to address the increasing challenges on manufacturing of components, including lightweight design and rising geometric complexity, the challenge emerges to further improve existing fabrication processes. In particular, drive train applications include filigree part geometries and functional elements, which is demanding for forming technology. Sheet-Bulk metal forming (SBMF) provides an option for addressing these issues in the production of planar and functional integrated parts. This approach uses bulk forming operations on sheet metals and leads to complex three dimensional strain and stress states during forming and thus incomplete die filling of functional elements as a consequence of unintended material flow. As a result of this central challenge of SBMF, locally modified tool surfaces, so called Tailored Surfaces, are used to control the material flow and improve the process results. In order to analyze the impact of Tailored Surfaces on the functional component properties, 1.0338 (DC04) and 1.0480 (HC260LA) are used in a SBMF forward extrusion process. Thereby, a locking tooth as a model geometry is formed. In the area of the functional elements, the active tool parts are in a laser polished condition, whereas the remaining tool areas are abrasive blasted to reduce the unintended material flow. Based on a parameter study varying the counterholder pressures during the forming process, the effect of the tool surfaces and the process parameters on the components surface properties are investigated by means of a confocal laserscanning microscope and tactile roughness measurements. In addition, measurements with an X-Ray diffractometer are carried out in order to analyze residual stress state of the formed parts.<br

Influence of Temperature on Yield Loci of Magnesium Alloy - Hußnätter, Wolfgang (Proceedings of LANE 2007, 2007)
LFT Import::2019-08-05 (1434)

Influence of the coating process on the tribological conditions during cold forging with a MoS2 based lubricant - Lorenz, Robby; Hagenah, Hinnerk; Merklein, Marion (AIP Conference Proceedings, 2018)
Cold forging processes such as forward rod extrusion can be used to produce high quality components like connection rods, shafts and gears. The main advantages of these extruded components are sufficient surface quality, work hardening, compressive residual stresses and fatigue strength. Since one technical disadvantage of extruded components lies in the achievable tolerance classes, the improvement of these should be of crucial importance. For instance, the attainable workpiece accuracy and component quality can be influenced by adapting the tribological system in such a way that the resulting friction is specifically controlled in order to improve component forming. Lubricant modification is one practical way of adapting the tribological system to the requirements of the forming process. An industrial established and highly efficient lubricant system is the application of a zinc-phosphate conversion layer with a molybdenum disulfide-based lubricant. While offering many advantages, its tribological conditions seem to depend strongly on the layer weight and the application strategy. These parameters and the respective interdependencies have not been sufficiently investigated yet. In order to examine this, the tribological conditions depending on the layer weight are analyzed in greater detail using the Ring-Compression-Test (RCT). This tribometer provides a comparative representation of the forming conditions during cold forging. Furthermore, a potential dependency between the tribological conditions and two different coating techniques is analyzed. The latter are represented by the industrial standards dipping and dip-drumming.<br

Influence of the Cutting Edge Geometry on the Tool Stress Distribution in Monocrystalline Silicon Punches for Microblanking of Thin Metal Foils - Hildering, Sven; Engel, Ulf; Merklein, Marion (Proc. 10th Int. Conf. Multi-Material Micro Manufacture, 2013)
LFT Import::2019-08-05 (1908)

Influence of the forming induced hardening on the wear behavior of aluminum gears within a metal-plastic material pairing and targeted adaption - Rohrmoser, Andreas; Hagenah, Hinnerk; Merklein, Marion (Procedia Manufacturing, 2021)
The material pairing metal-plastic offers advantages such as a reduced weight and the ability to be operated in dry conditions, but the application is limited due to the occurring wear. The properties of the metallic gearing have a significant influence on the wear behavior. From previous investigations on the application of steel within the material pairing, the influence of the surface topography and the load case is known. With regard to further weight reduction, the application of light metals such as aluminum is promising. However, the low strength of aluminum poses a challenge due to the low wear resistance. The properties of the metallic gearing are not only determined by the choice of material but also by the manufacturing process. In this context, cold extrusion offers potential for the production of ready-to-use gears. Sufficient geometrical properties and a substantial increase in tooth flank hardness are achieved. In this contribution, the influence of the forming induced hardening on the wear behavior of aluminum gears was investigated. Wire eroded aluminum and steel gears were used for comparison. The low hardness of conventionally manufactured aluminum gears was identified as a major challenge. Subsequently, gears with significantly higher tooth flank hardness were manufactured in an adapted full-forward extrusion process and the improved wear behavior was verified. Finally, functional correlations regarding the hardness of the metal pinion and the resulting wear behavior were derived.
CRIS-Team Scopus Importer:2021-11-05
Keywords: Aluminum; Cold-forging; Gears; Metal-plastic; Polymer; Wear

Influence of the forming process on springback - Durmaz, U.; Heibel, S.; Schweiker, T.; Prabhakar, A.; Merklein, Marion (INTERNATIONAL DEEP-DRAWING RESEARCH GROUP CONFERENCE (IDDRG 2022), 2022)
CRIS-Team WoS Importer:2023-01-20

Influence of the Material Combination on the Load-bearing Capacity of Shear-clinched Joints - Wiesenmayer, Sebastian; Graser, Matthias; Merklein, Marion (1st International Conference on Advanced Joining Processes AJP 2019, 2019)

Influence of the mechanical fatigue progress on the magnetic properties of electrical steel sheets - Karthaus, Jan; Steentjes, Simon; Gröbel, Daniel; Andreas, Kolja; Merklein, Marion; Hameyer, Kay (Archives of Electrical Engineering, 2017)
The purpose of this paper is to study the variation of the magnetic properties of non-oriented electrical steel sheets with the fatigue state during cyclic mechanical loading. The obtained results are central to the design of variable drives such as traction drives in electric vehicles in which varying mechanical loads, e.g. in the rotor core (centrifugal forces), alter the magnetic properties. Specimens of non-oriented electrical steel are subject to a cyclically varying mechanical tensile stress with different stress amplitudes and number of cycles. The specimens are characterised magnetically at different fatigue states for different magnetic flux densities and magnetising frequencies. The measurements show a variation in magnetic properties depending on the number of cycles and stress magnitude which can be explained by changes in the material structure due to a beginning mechanical fatigue process. The studied effect is critical for the estimation of the impact of mechanical material fatigue on the operational behaviour of electrical machines. Particularly in electrical machines with a higher speed where the rotor is stressed by high centrifugal forces, material fatigue occurs and can lead to deterioration of the rotor's stack lamination.
LFT Import::2019-07-29 (2242)
Keywords: Cyclic mechanical stress; electrical machines; electrical steel sheets; magnetic properties; material fatigue

Influence of the plasticity strain gradient on springback in micro-bending process of metal foils - Li, H. Z.; Dong, X. H.; Shen, Y.; Diehl, Alexander; Hagenah, Hinnerk; Engel, Ulf; Merklein, Marion (Proceedings of The 2nd Asia Conference on micro/nano sized technology (AWMFT-2009), 2009)
LFT Import::2019-08-05 (133)

Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel - Kuball, Clara-Maria; Jung, Robert; Uhe, Benedikt; Meschut, Gerson; Merklein, Marion (Journal of Advanced Joining Processes, 2020)

Influence of the process temperature on the tribological behaviour during bulk forming of high nitrogen steel - Kuball, Clara-Maria; Jung, Robert; Uhe, Benedikt; Meschut, Gerson; Merklein, Marion (1st International Conference on Advanced Joining Processes AJP 2019, 2019)

Influence of the process time on a self-piercing riveting process with tumbling kinematic - Wituschek, Simon; Elbel, Leonie; Lechner, Michael (3rd International Conference on Advanced Joining Processes 2023, 2023)

Influence of the process time on a self-piercing riveting process with tumbling kinematic - Wituschek, Simon; Elbel, Leonie; Lechner, Michael (Proceedings of the Institution of Mechanical Engineers Part E-Journal of Process Mechanical Engineering, 2024)
The increasing significance of ecological responsibility, stricter political regulations and economic objectives are driving innovation in research fields such as lightweight construction. One of the most important popular methods is the use of multi-material systems. Due to the different geometric and mechanical properties of the various materials used, resource efficient applications and utilizations are possible. Great challenges arise for the joining processes to realize these multi-material systems, since conventional joining processes reach their limits. In the field of mechanical joining processes, there are continuously new approaches, such as superimposing the punch in a self-piercing riveting process with a tumbling kinematic, to increase the number of adaptable process parameters and enhance the process control. Through various preliminary tests, a good understanding of the process has been developed, which allows to directly control the geometric joint parameters by configuring the tumbling strategy. A major challenge, particularly with regard to future industrial applications, is the process time, which is comparatively high due to the tumbling kinematics. In the investigations, a reduction of approximately 90% of the process time is targeted by adapting the joining and tumbling strategy. Therefore, the correlation of the traverse velocity and the tumbling velocity are examined in a gradual series of experiments. To represent realistic applications, the experiments are carried out with a dual-phase steel and a precipitation-hardening aluminum alloy. For identifying the influence of the process parameters on the joining process, a constant rivet–die combination is applied. Further, the examination of force–displacement curves is conducted. Moreover, the determination of geometric joint parameters is reliant upon macrographs to assess the influence of the joining time on the geometric joint formation. The test results show that a significant increase in joining speed with a resulting reduction in process time is feasible. Although the joining properties are affected, reliable joining is possible. In particular, the shaft thickness of the rivet is influenced by the varying proportion of the tumbling process in the joining operation and increases with higher joining speeds.<br
Keywords: Mechanical joining; self-piercing riveting; multi-material systems

Influence of the properties of the joining partners on the load-bearing capacity of shear-clinched joints - Wiesenmayer, Sebastian; Graser, Matthias; Merklein, Marion (Journal of Materials Processing Technology, 2020)
Shear-clinching requires a minimum ductility for the punch-sided sheet material. A promising approach to overcome this limitation is a local short-term heat treatment of the upper joining partner in the joining zone. However, the design of heat treatment layouts for high-strength aluminum alloys necessitates fundamental knowledge on the mechanisms in shear-clinching processes in dependence of the properties of both joining partners. Therefore, within the paper, the mechanisms in shear-clinching were analyzed for a common aluminum magnesium alloy of the 5000 series, an alloy of the 6000 series with higher strength and a high-strength alloy of the 7000 series. On the die-side, hot stamped 22MnB5 and the dual phase steel HCT780X was utilized. For upper sheet materials with higher strength, the radial material extrusion of the upper joining partner decreases, which leads to the increase of the material volume in the joining zone and therefore to a larger bottom thickness and interlock. In addition, the decreased penetration of the outer punch results in a larger upper neck thickness. Due to the larger load-bearing cross section and the higher tensile strength, higher forces can be transmitted for high-strength materials. However, the low ductility of high-strength materials results in a failure of the joint at lower displacements and therefore in a decreased energy absorption. The found mechanisms provide the theoretical basis for the design of heat treatment layouts for high-strength aluminum alloys.
CRIS-Team Scopus Importer:2020-04-24
Keywords: Heat treatment; High-strength aluminum; High-strength steel; Joining; Multi-material design

Influence of the rivet coating on the friction during self-piercing riveting - Uhe, Benedikt; Kuball, Clara-Maria; Merklein, Marion; Meschut, Gerson (Key Engineering Materials, 2021)

Influence of the strain dependent material behaviour under plane strain on the yield locus modelling - Lenzen, Matthias; Merklein, Marion (INTERNATIONAL DEEP-DRAWING RESEARCH GROUP CONFERENCE (IDDRG 2021), 2021)
CRIS-Team WoS Importer:2021-11-05

Influence of the Textile Reinforcement on the Joint Formation of Pin-Joined Composite/Metal Parts - Popp, Julian; Drummer, Dietmar (Applied Composite Materials, 2024)

Influence of the Variation of Material Properties on the Risk of Failure in Dependency of the Materials Flow Condition during Forming Processes - Sturm, Vera; Merklein, Marion; Bernhard, Oberpriller (International Journal of Material Forming, 2010)
LFT Import::2019-07-29 (314)
Keywords: Failure risk; Sheet metal forming; Variation of materials properties

Influence of Tool Surface on Tribological Conditions in Conventional and Dry Sheet Metal Forming - Merklein, Marion; Andreas, Kolja; Steiner, Jennifer (International Journal of Precision Engineering and Manufacturing - Green Technology, 2015)
LFT Import::2019-07-29 (2086)
Keywords: Dry forming; Sheet metal forming; Tribology

Influence of tool wear on the load-bearing capacity of shear-clinched joints - Wiesenmayer, Sebastian; Merklein, Marion (Defect and Diffusion Forum, 2020)
Shear-clinching allows the joining by forming of dissimilar materials with high differences between their mechanical properties without additional fasteners. Since the lower joining partner is indirectly shear cut during the process, even ultra-high strength materials can be joined. However, the cutting of the high-strength materials as well as the extrusion of the upper joining partner leads to high process forces and therefore to high tool loads. This applies in particular for the die, which is highly stressed during the cutting phase and therefore plastically deformed. Within the scope of this work, the influence of the occurring wear on the formation of the joint and its load-bearing capacity is analyzed for a scope of 500 strokes. For this purpose, press hardened 22MnB5 is used as lower joining partner. Its high strength leads to the plastic deformation of the cutting edge, which increases within the first 200 strokes. Afterwards only minor changes occur. Yet, no effect of the occurring wear on the joint formation and the joint strength, which was tested under shear and tensile load, could be determined. Functioning joints could still be produced for more than 500 strokes as the load-bearing capacity remained on a comparable level.
CRIS-Team Scopus Importer:2020-12-04
Keywords: High-strength steel; Joining; Wear

Influence of tribological conditions on application relevant component properties of cold forged gears - Rohrmoser, Andreas; Kiener, Christoph; Hagenah, Hinnerk; Merklein, Marion (Production Engineering, 2019)

Influence of tribological conditions on cold forging of gears - Kiener, Christoph; Neher, R.; Merklein, Marion (Production Engineering, 2018)
Gears are integral and vital machine elements in the field of drive and transmission technology. With regard to economic and ecological aspects, cold forging represents a promising approach compared to conventional cutting processes for producing highly-loadable gears. A possible extrusion process for manufacturing helical gears is the so-called “Samanta”-process. In comparison to conventional extrusion processes, an additional ejector system is avoidable. Thus, in particular for helical gears, a negative impact on the gear quality by the ejector operation is prevented. Furthermore, the process chain during the component production cycle is shortened which leads to a more efficient production. The achievable gear accuracy as well as insufficient tool life are major challenges while establishing the “Samanta”-process in industry. To enable an industrial application, basic process understanding as well as knowledge about the influences on the process results is required. For influencing component and process properties within cold forging, approaches from the tribological system can be generally used. The aim of this study is to analyze the influence of the friction conditions on selected component and process properties within cold forging of gears by the “Samanta”-process. For adjusting the occurring friction, various lubrication systems were applied, which have been qualified using a double cup extrusion test (DCE-test). The results reveal that the lubrication system determines the friction conditions during forming. Within cold forging of helical gears by the “Samanta”-process, the friction influences the resulting strain hardening of the components and the required maximum forming force as well as the energy amount.
LFT Import::2019-07-29 (2285)
Keywords: Cold forging; Friction; Gears; Tool technology

Influence of tribological conditions on cold forging processes - Kiener, Christoph; Dohmstreich, J.; Andreas, Kolja; Merklein, Marion (Proceedings THE"A" Coatings, 2017)
LFT Import::2019-08-07 (2262)

Influence of Ultrasonic Assistance on the Forming Limits of Steel - Jäckisch, Manuel; Merklein, Marion (Minerals, Metals and Materials Series, 2021)
Since Blaha discovered the beneficial effect of superimposing high-frequency oscillations to the metal forming process, the occurring force and stress reduction are well-known phenomena. Leading to an immediate flow stress reduction, the so-called ultrasonic assistance is a promising approach to enable forming with reduced process forces. While the achievable force reduction has been investigated intensively, only a few analyses have been conducted in the context of the impact of ultrasonic superposition on the forming limits. The latest investigations state earlier material failure due to localized forming with recurrent high strain rates. Within this paper, the influence of superimposed vibrations on the forming limits of C35E is investigated with regard to distinct oscillation amplitudes and press velocities. It was found that superimposed 20 kHz oscillations of 10 and 20 µm cause considerable earlier material failure. In comparison to conventional testing, the crack initiation, as well as the shear zone formation, is alternated due to the ultrasonic assistance.
CRIS-Team Scopus Importer:2021-09-03
Keywords: Failure; Forming; Steel; Ultrasonic

Influence of ultrasonic vibration on the shear formability of metallic materials - Michalski, Markus; Lechner, Michael; Gruber, Micha; Merklein, Marion (CIRP Annals - Manufacturing Technology, 2018)
The flow stress reduction of metallic materials due to superimposed ultrasonic vibration is an intensively researched phenomenon. So far, however, only a few studies have analysed the vibrational influence on forming limits. Existing findings are inconsistent, suggesting both a formability extension and a decrease. Ultrasonic-assisted shear tests constitute a novel experimental approach for the fundamental investigation of predominant cause–effect–relationships. The test results reveal a distinct correlation between the application of ultrasonic vibration and earlier material failure. This effect is attributed to enhanced crack initiation and propagation caused by localised stress and strain concentration as well as intermittent high strain rates.
LFT Import::2019-07-29 (2298)
Keywords: Failure; Forming; Ultrasonic

Influence of upscaling accumulative roll bonding on the homogeneity and mechanical properties of AA1050A - Ruppert, Mathis; Böhm, Wolfgang; Nguyen, H.; Höppel, Heinz Werner; Merklein, Marion; Göken, Mathias (Journal of Materials Science, 2013)
Accumulative roll bonding (ARB), as a method for production of ultrafine grained materials, is frequently supposed to be easily transferable to established industrial production lines. In literature, however, common sheet dimensions used for ARB in a laboratory scale are between 20 and 100 mm in width. In order to quantify the potential of upscaling the ARB process to a technological relevant level, sheets of AA1050A with an initial sheet width of 100–450 mm were accumulative roll bonded up to 8 cycles. In this regard, three different rolling mills of distinct dimensions were used for processing of the sheet material. The influence of process parameters and the reproducibility of the process, in terms of mechanical properties and homogeneity of the sheets, were studied by means of mechanical and microstructural characterization. Both appear to be largely independent on the sheet size and the rolling mill utilized for production. Only small deviations after the first cycles could be detected, vanishing in subsequent cycles due to the features of microstructural evolution. The finally obtained results indicate a high potential for industrial application of ARB and illustrate the possibility to upscale the process to a level necessary for that purpose.
WW1::970

Influence of varying sheet material properties on dry deep drawing process - Krachenfels, Kim; Rothammer, Benedict; Zhao, Rong; Tremmel, Stephan; Merklein, Marion (IOP Conference Series: Materials Science and Engineering, 2019)
Deep drawing is one of the most important processes in sheet metal forming. Conventionally, lubricants are used to reduce friction and wear. Demands for increased sustainability, environmental protection and resource efficiency motivate the realization of lubricant-free forming processes. The direct contact between tool and workpiece during dry deep drawing results in changed tribological conditions, which cause an increase in friction and wear. Friction-reducing surface modifications of the tool such as carbon based coatings are being developed for the adaptation of the tribological conditions. The aim of this work is the simulation-based analysis of the stress spectrum for varying sheet properties for the qualification of wear-reducing surface modifications for a wide range of applications. By a simulation model for a rectangular cup, the influence of different batches of steel and aluminum materials with varying friction coefficients and mechanical properties is investigated within the framework of variant simulations. The tribological conditions in the simulation are described on the basis of friction coefficients from the strip drawing test. From the simulation results, the applicability of surface modifications for dry deep drawing is being evaluated depending on the sheet specific properties.<br

Influence of Warm Bending on the Surface Topography of Titanium Alloy Ti-6Al-4V - Dubjella, Patrick; Merklein, Marion (Procedia Engineering, 2017)
More frequently industry reverts to titanium alloys such as Ti-6Al-4V for several applications. This is due to its wide range of positive material characteristics like high biocompatibility, good corrosion resistance and high specific strength. Hence, Ti-6Al-4V is utilized for applications in medicine technique, marine and aerospace. However, forming of Ti-6Al-4V at room temperature is limited, which is caused by its hexagonal closed packed (hcp) grain structure. To overcome these limitations it is necessary to form Ti-6Al-4V at elevated temperatures. Thus, further gliding planes are activated and large scaled parts can be formed at low cycle times. Another promising process to generate Ti-6Al-4V structures is additive manufacturing. Via Laser Beam Melting (LBM) geometrical limitations of the forming process can be overcome. Nearly every conceivable geometry like undercuts is possible to generate. However, the process takes comparatively long time and the costs for large batch sizes are high. In order to merge the advantages of forming and LBM a combination of both processes is favorable. The sequence of forming and a subsequent additive process to produce a hybrid part leads to several challenges. Besides forming induced residual stresses in the sheet metal, the topography of the sheet has effect on the bonding quality of sheet metal and additive structure. Especially peaks in roughness may serve as crack initiators. In order to provide suitable parts for the subsequent additive process it is necessary to have a sound knowledge of the impact of the forming operation on the surface topography. For this reason this paper focuses on the investigation of the influence of warm bending on the surface topography of Ti-6Al-4V. Therefore bending tests with varying temperatures, punch radii and different bending angles are conducted and the topography is analyzed with confocal microscopy.
LFT Import::2019-07-29 (2260)
Keywords: Additive Manufacturing; Bending; Titanium

Influences of indentation forming on surface characteristics and metallographic properties of bright finishing alloys - Beck, Johannes; Friedrichsen, M.; Merklein, Marion (7. WGP-Jahreskongress Aachen, 5.-6. Oktober 2017, 2017)
LFT Import::2019-08-05 (2257)

Influences of Nozzle Material on Laser Droplet Brazing Joints with Cu89Sn11 Preforms - Stein, Stefan; Heberle, Johannes; Gürtler, Franz-Josef; Cvecek, Kristian; Roth, Stephan; Schmidt, Michael (Physics Procedia, 2014)
This paper presents latest results on the influences of nozzle material and geometry on the electromechanical contacting of sensitive piezoceramic actuator modules. Two nozzle types have been investigated,a standard WC/Co nozzle which is used for soldering applications and a novelceramic nozzle. Applications for active piezoceramic components integrated in structural parts are e.g. active damping, energy harvesting, or monitoring of vibrations and material failure. Anup to now unsolved problem is the electrical contacting of such components without damaging the conductor or the metallization of the ceramic substrate. Since piezoelectric components are to be integrated into structures made of casted aluminum, requirements are high mechanical strength and temperature resistance. Within this paper a method forcontacting piezoceramic modules is presented. A spherical braze preform of tin bronze Cu89Sn11 with a diameter of 600 μm is located in a ceramic nozzle and is subsequently melted by a laser pulse. The liquid solder is ejected from the nozzlevia nitrogen overpressure and wets the surface of the metallization pad and the Cu-wire, resulting in a brazing joint after solidification. The process is called laser droplet brazing (LDB). To asses the thermal evolution during one cycle WC/Co and ZTA have been simulated numerically for two different geometries enabling a proposition weather the geometry or the material properties have a significant influence on the thermal load during one cycle. To evaluate the influence of the nozzle on the joint the positioning accuracy, joint height and detachment times have been evaluated. Results obtained with the ZTA nozzle show comparable positioning accuracies to a WC/Co nozzle with a lower standard deviation of solder detachment time.
Keywords: laser soldering; brazing; piezoceramic; bonding; laser droplet brazing

Influences on the Molding in Hydroforming Using Granular Material as a Medium - Grüner, Martin; Merklein, Marion (AIP Conference Proceedings Volume 1383 - The 8th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes (NUMISHEET 2011), 2011)
The need of lightweight construction for the body in white of modern cars increases due to legal restrictions of CO2 emissions and the passenger s wishes of safety and low fuel consumption. On e approach of lightweight construction is the use of high and ultra high strength steel, to reduce the weight of the single parts, another approach is the use of modern forming technologies, e.g. hydroforming with the possibility to create undercuts, to produce complex parts and thus to reduce the number of parts, the number of joining operations and the weight. The mentioned ultra high strength steels show a poor formability at room temperature and the necessary process forces are high compared to standard deep drawings teels. Warmforming operations can help to reduce the process forces and to increase formability [1]. To combine the benefits of warm forming and hydroforming new forming media are necessary to overcome the problem of temperature stability of fluids, which is limited to about 350 °C [2]. Beside gases, which tend to leakage and which are highly compressible, granular material like small ceramic beads can be used as a forming medium. First results of forming operations using this medium were presented in [3]. The experimental tool used for those tests pressurizes the medium by a punch. To divide the effects caused by temperature and steel grade from the other effects experiments were carried out at room temperature using the well know n deep drawing steel DC04. Influences of the ceramic beads diameter, the number of repetitions, the punch geometry as the punch position, determining the volume of media, on the forming are presented. © 2011 American Institute of Physics.
LFT Import::2019-08-05 (1757)
Keywords: Elevated temperatures; Granular material; Hydroforming

Influences on wear load in cup extrusion processes - Schrader, Tobias; Engel, Ulf; Merklein, Marion (7th ICFG Workshop on Process Simulation in Metalforming, 2012)
LFT Import::2019-08-05 (1843)

Inkrementelles Umformen dünnwandiger Funktionsbauteile unter Einsatz prozessangepasster Halbzeuge durch Verfahren der Blechmassivumformung - Hildenbrand, Philipp; Sieczkarek, P.; Matthias, S.; Löffler, Maria; Besserer, H. (Tagungsband zum 18. Workshop Simulation in der Umformtechnik & 3. Industriekolloquium Blechmassivumformung 2015 - DFG Transregio 73, 2015)
LFT Import::2019-08-05 (2078)

In-Line strategies and methods to reduce balancing efforts within rotor production for electric drives - Hofmann, Benjamin; Masuch, Michael; Frey, Philipp; Franke, Jörg; Merklein, Marion (6th International Electric Drives Production Conference (EDPC), 2016)
Within a research project focussing the optimization of the entire process chain of rotor production, balancing is identified as one of the processes with a high potential for innovation. As most research efforts concentrate on the additive or subtractive process itself, the presented paper follows a different approach concentrating on the impact of process steps prior to rotor assembly and the actual balancing operation. Within current production processes, weighing is almost exclusively performed as an end-of–line process to take the entire rotor assembly into account. However, concerning the production of drives with permanent magnets, particularly those with magnets integrated into the lamination stack (IPM-Drives), production steps leading to the rotor assembly already deliver prefabricated lamination modules that can be evaluated regarding their imbalance. By determining the imbalance of those modules and a varying rotational combination of a number of modules being needed to form a complete rotor assembly, balancing efforts are considered to be reduced significantly; resulting in a lighter rotor assembly due to thinner end caps on the rotor. The presented Paper describes methods and strategies to evaluate the imbalance of single lamination stacks and their preferred orientation prior to their assembly onto the rotor shaft. Depending on the rotor topology (pole number, magnet count), restrictions regarding free rotation have to be considered. Additionally, known methods for balancing in single and double layers have to be practically analysed and compared for the balancing operation in focus. Using pre-stacked laminations, the balancing operation is validated in practice to determine actual effects on the imbalance of a complete lamination stack. Using different combinations for aggregating single packages, the imbalance can be reduced by up to 30%.<br
Keywords: balancing; rotor; electric drives

Innenhochdruckumformen mit erwärmtem Medium - eine Leichtbautechnologie für die Aluminium- und Magnesium- Halbzeugumformung - Stich, A.; Celeghini, Martino; Novotny, Stefan; Geiger, Manfred; Haldenwanger, H.G. (Tagungsband zum 7. Dresdner Leichtbausymposium "Interaktionsfeld Leichtbau - Effizienzsteigerung durch dichtere Vernetzung", 26.-28. Juni, Dresden, 2003)
LFT Import::2019-08-05 (956)

Innenhochdruck-Umformen verstärkter Blech-Rahmenstrukturen - Tolazzi, Massimo (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2008)
Modern lightweight concepts are characterised by a specific application of tailored materials, new production technologies as well as complex components. This work, in which Tailor Welded Blanks should be formed into complex frame structures faces up one of the main topics of Lightweight. Aim of this work was on the one hand to extend the field of application of sheet hydroforming, by means of fundamental investigations, to complex frame structures and at the same time to define suitable process strategies and process limits with the support of analytic and numeric methods. On the other hand the application of sheet hydroforming as a forming technology for Tailor Welded Blanks should be investigated aiming at the definition of general process design strategies for the productio

Innenhochdruck-Umformen von Blechpaaren: Modellierung, Prozeßauslegung und Prozeßführung - Hein, Philipp (Friedrich-Alexander-Universität Erlangen-Nürnberg, 1999)
The hydroforming of sheet metal pairs is a new process that will find its applications in the production of structural components of car bodies-in-white. In this process, the two blanks are deformed simultaneously by a pressurized fluid which is injected in the hollow space between them, while the rims of the blanks are kept tight. The target of the research was to develop a profound knowledge of the effects influencing the process and to provide the fundamentals for future industrial applications. The process has been modelled analytically and in finite element analysis to identify the main influencing parameters. Special attention has been devoted to the coupling of the deformations of the two blanks which can be welded together or not. The process limits (loss of tightness, bursting) and characteristic curves (e.g. clamping curve), which have been determined theoretically and experimentally, have been brought together in a process window that can be used for the process layout. Finally, process control strategies have been developed and verified in order to obtain an optimal process efficiency. This included the search for optimal load paths and the implementation of closed-loop control mechanisms for the distribution of blank-holder pressure

Innenhochdruck-Umformen von Blechpaaren - Technologie für den modernen Leichtbau - Vahl, Meik; Novotny, Stephan; Celeghini, Martino; Kreis, Oliver (Idee-Vision-Innovation, 2001)
LFT Import::2019-07-15 (831)

Innenhochdruck-Umformen von Doppelblechen - Geiger, Manfred; Neugebauer, Stephan; Merklein, Marion; Lamprecht, Klaus; Tolazzi, Massimo; Bahn, V. (Wirkmedienbasierte Fertigungstechniken zur Blechumformung, Abschlussbereicht zum DFG-Schwerpunktprogramm SPP 1098, 28.-29.09., Dortmund, 2006)
LFT Import::2019-08-05 (1298)

Innenhochdruck-Umformen von Magnesiumblechen - Merklein, Marion; Hecht, Joachim; Hußnätter, Wolfgang; Geiger, Manfred (Karosserie II, 2006)
LFT Import::2019-07-16 (1312)

Innovationen in der Automobilproduktion als Schlüssel zu nachhaltiger Wettbewerbsfähigkeit - Eßer, Gerd (Proceedings XII. Internationales Produktionstechnisches Kolloquium PTK 2007, 2007)
LFT Import::2019-08-05 (1469)

Innovationen in der Blechbearbeitung durch Integration der Lasertechnik in die Blechumformung - Geiger, Manfred; Hein, Philipp (Aachener Kolloquium für Lasertechnik, 1995)
LFT Import::2019-08-05 (544)

Innovationsmanagement für Laserstrahltechnologien: Strategische Überlegungen und ausgewählte Technologiebeispiele. - Hutfless, Joachim; Geiger, Manfred (Innovation und Kundennähe: Wachstumsstrategien im Wettbewerb. Tagungsband Müncher Management Koloquium, 1996)
LFT Import::2019-08-05 (660)

Innovative Aluminium Lightweight Design by the Combination of Accumulative Roll Bonding and Local Intermediate Heat Treatment - Böhm, Wolfgang; Merklein, Marion; Lechner, Michael (Materials Today, 2015)
The intensifying regulations for CO2 emissions of passenger cars lead to increased efforts in the field of lightweight construction. In this context, the application of aluminium is a promising strategy. Another approach is the implementation of high strength materials to enable the reduction of the wall thickness of components and to ensure the crash performance. The manufacturing of multi-layered aluminium sheet metal with enhanced strength and nanocrystalline grain structure can be performed using the Accumulative Roll Bonding process (ARB). However, the formability of ARB processed aluminium is relatively poor. Therefore, within this paper an innovative approach to enhance the formability is presented. Key idea of the local short term intermediate heat treatment is the tailoring of the mechanical properties between two forming operations. In order to identify suitable process parameters for beneficial heat treatment, the interaction of pre-straining and heat treatment is evaluated.
EAM Import::2019-03-13

Innovative approaches for controlling the material flow in sheet-bulk metal forming processes - Merklein, Marion; Lechner, Michael; Gröbel, Daniel; Löffler, Maria; Schneider, Thomas; Schulte, Robert Karl; Hildenbrand, Philipp (Manufacturing Review, 2016)
Using sheet-bulk metal forming processes the application of bulk forming operations on sheet metals enables the manufacturing of functional components with local wall thickness variations. As these processes come along with a two- and three-dimensional material flow, the control of the material flow is crucial for ensuring a proper filling of functional elements and thus ensuring the components quality. Controlling the material flow can be achieved by different solutions: the local adaption of tribological conditions and the application of process adapted semi-finished parts. In this paper, both solutions as well as their general qualification in two sheet-bulk metal forming processes are presented.
LFT Import::2019-07-29 (2144)
Keywords: Forming; Material flow; Processes

Innovative Fertigungstechnologien für Strukturbauteile - Gnibl, Tobias (Technik in Bayern, 2012)
LFT Import::2019-07-29 (1789)

Innovative Fertigungsverfahren für Aluminiumschaum und Aluminium-Schaum-Sandwich (AFS) - Hahn, Markus; Schöberl, T.; Otto, Andreas (Idee-Vision-Innovation, Festschrift anläßlich des 60. Geburtstages von Professor Manfred Geiger, 2001)
LFT Import::2019-07-15 (838)

Innovative Kombinationen - Wirkmedienbasierte Umformung von Tailored Welded Blanks und Patchwork Blanks - Geiger, Manfred; Tolazzi, Massimo; Lamprecht, Klaus (Uni-Kurier-Magazin, 2004)
LFT Import::2019-07-16 (1107)

Innovative laser based micro joining techniques in electronics production - Albert, F.; Jahrsdörfer, Bernd; Mys, I.; Schmidt, Michael (The Laser User, 2005)
LFT Import::2019-07-16 (1215)

Innovative laserbasierte Fügeverfahren zur elektrisch leitfähigen Kontaktierung - Schmidt, Michael; Albert, F.; Jahrsdörfer, Bernd; Mys, I. (Laser Workshop, Moderne Lasertechnologien und ihre Anwendungen, 2002)
LFT Import::2019-08-05 (1708)

Innovative Lösungen zu selektiven Fügeaufgaben in der Elektronikproduktion - Albert, F.; Jahrsdörfer, Bernd; Mys, I. (Tagungsband des 7. Erlanger Seminars Laser in der Elektronikproduktion und Feinwerktechnik, 2005)
LFT Import::2019-08-05 (1211)

Innovative Manufactring Chain for Complex Hydroforming Parts - Special Solutions for Process and Systems Technology - Geiger, Manfred; Merklein, Marion; Blankl, Andreas (Proceedings of the 22nd International Manufacturing Conference (IMC), 2005)
LFT Import::2019-08-05 (1198)

Innovative manufacturing solutions for the efficient production of car bodies - Merklein, Marion; Tsoupis, Ioannis; Gnibl, Tobias; Lechner, Michael (Forming in Car Body Engineering 2015, 2015)
LFT Import::2019-08-05 (2123)

Innovative mechanical joining processes in versatile process chains - potentials, applications and selection procedures - Lechner, Michael; Kappe, Fabian; Römisch, David; Rostek, Tim; Wituschek, Simon (Materials Research Proceedings, 2023)

Innovative Methoden zur Charakterisierung des Fließverhaltens und des Werkstoffversagens von Blechwerkstoffen - Merklein, Marion; Kuppert, Andreas; Biasutti, Manfredi; Lupino, Roberto (testXpo - 18. Fachmesse für Prüftechnik, 2009)
LFT Import::2019-08-05 (199)

Innovative Process Strategies in Powder-Based Multi-Material Additive Manufacturing - Setter, Robert; Hafenecker, Jan; Rothfelder, Richard; Kopp, Sebastian-Paul; Roth, Stephan; Schmidt, Michael; Merklein, Marion; Wudy, Katrin (Journal of Manufacturing and Materials Processing, 2023)
Multi-material additive manufacturing (AM) attempts to utilize the full benefits of complex part production with a comprehensive and complementary material spectrum. In this context, this research article presents new processing strategies in the field of polymer- and metal-based multi-material AM. The investigation highlights the current progress in powder-based multi-material AM based on three successfully utilized technological approaches: additive and formative manufacturing of hybrid metal parts with locally adapted and tailored properties, material-efficient AM of multi-material polymer parts through electrophotography, and the implementation of UV-curable thermosets within the laser-based powder bed fusion of plastics. Owing to the complex requirements for the mechanical testing of multi-material parts with an emphasis on the transition area, this research targets an experimental shear testing set-up as a universal method for both metal- and polymer-based processes. The method was selected based on the common need of all technologies for the sufficient characterization of the bonding behavior between the individual materials.<br
Keywords: additive manufacturing; multi-material additive manufacturing; polymers; metals; shear testing; mechanical testing; powder bed fusion; binder jetting; electrophotography; vibration dispenser

Innovative Prozesskette für Strukturleichtbauteile - Verarbeitung von Aluminium Tailored Blanks bei erhöhten Temperaturen - Gnibl, Tobias; Merklein, Marion (wt Werkstattstechnik - Online, 2014)
LFT Import::2019-07-29 (2035)

Innovative Sitzbauteile durch Umformen von Mehrphasenstählen - Kaupper, Markus; Merklein, Marion; Weidinger, Peter (Maschinenmarkt, 2011)
LFT Import::2019-07-29 (1659)

Innovatives Konstruktions- und Fertigungskonzept für Straßenbahn-Rohbau - Celeghini, Martino; Pohl, Thomas; Geiger, Manfred; Merklein, Marion; Hecht, Joachim; Meerkamm, H.; Stockinger, A. (8. Fachtagung Fügen und Konstruieren im Schnienfahrzeugbau, 2009)
LFT Import::2019-08-05 (1584)

Innovative solutions for selective laser micro joining in electronic production - Mys, I.; Albert, F.; Jahrsdörfer, Bernd; Schmidt, Michael (Proceedings of the 3rd International WLT-conference on Lasers in Manufacturing, 2005)
LFT Import::2019-08-05 (1213)

Innovative Technologien für den Blech-Leichtbau - Geiger, Manfred; Meyer-Pittroff, Frank (Dresdner Leichtbausymposium, 1998)
LFT Import::2019-08-05 (1591)

Innovative Tribological Systems in Sheet Metal Forming - Revolution in the Press Shop? - Andreas, Kolja; Tenner, Jennifer; Vierzigmann, Ulrich; Merklein, Marion; Tremmel, Stephan; Zhao, R. (Proc. 11th Int. Conf. THE "A" Coatings in Manufacturing Engineering, 2014)
LFT Import::2019-08-05 (2048)

Innovative Werkzeugtechnik für die Kaltmassivumformung - Arbak, Murat; Wagner, Kay (Der Schnitt- & Stanzwerkzeugbau, 2007)
LFT Import::2019-07-16 (1390)

In-Process Measurement of Bending Angles - Geiger, Manfred; Heckel, Werner (Production Engineering, 1996)
LFT Import::2019-07-15 (642)

In-process measurement of spring-back in sheet metal bending. - Heckel, Werner (Sheet Metal 1996. Proc. of the 4th International Conference, Twente, NL, 1.-3. April (1996), 1996)
LFT Import::2019-08-05 (673)

In-process measurment of bending angles based on the principle of light sectioning - Heckel, Werner (International Archives of Photogrammetry and Remote Sensing, Nr. 29 Part B4, 1992)
LFT Import::2019-08-05 (491)

In Situ Formation of a Metastable β-Ti Alloy by Laser Powder Bed Fusion (L-PBF) of Vanadium and Iron Modified Ti-6Al-4V - Huber, Florian; Papke, Thomas; Scheitler, Christian Josef; Hanrieder, Lukas; Merklein, Marion; Schmidt, Michael (Metals, 2018)

In-situ-Ultraschallmessung der wahren Kontaktfläche bei Massivumformverfahren - Geiger, Manfred; Engel, Ulf; Vollertsen, Frank (Umformtechnik, 1993)
LFT Import::2019-07-15 (392)

In Situ Ultrasonic Measurement of the Real Contact Area in Bulk Metal Forming Processes. - Geiger, Manfred; Engel, Ulf; Vollertsen, Frank (CIRP Annals - Manufacturing Technology, 1992)
LFT Import::2019-07-16 (1965)
Keywords: contact area; forming; friction; interface; ultrasonics

Integrated manufacturing by hydroforming, laser welding and cutting - Kreis, Oliver; Celeghini, Martino; Merklein, Marion (Proceedings of the 11th International Conference on Sheet Metal, 2005)
The shortening of process chains and the combination of innovative manufacturing technologies offer the possibility to enhance the complexity of technical products. The presented work describes the development of a process chain for the manufacturing of complex hollow parts out of double sheets and tubes with a big variation of the cross section, e.g. for A-pillars in the automotive sector. Two blanks and a tube are inserted in a hydroforming tool by a handling robot. The processes forming of blanks and tubes as well as joining by clinching are integrated in this tool. After these steps, the handling robot places the part in a laser station, where integrated laser welding and cutting processes take place. This paper focuses on special solutions developed both in the hydroforming and in the laser processing. In particular, the connection between blanks and tube is extremely problematic with regard to the sealing in the hydroforming process and the welding operations due to an existing gap. The requested tightness is reached by reinforcing the tube in the connection area with a ring insert, by placing sealing profiles on the outer surface of the tube and particularly by adding a sealing medium to the hydroforming fluid. In laser operations, special challenges result from complex welding and cutting paths, contaminations of the blanks with hydroforming media and lubricants, gaps between the blanks that occur due to residual stresses after forming and burr formatio
LFT Import::2019-08-05 (1166)
Keywords: Hydroforming; Laser; Process

Integrated manufacturing by hydroforming, laser welding and cutting of complex hollow parts - Kreis, Oliver; Celeghini, Martino; Geiger, Manfred; Merklein, Marion (LANE 2004, Proceedings of the 4th International Conference on Laser Assisted Net Shape Engineering, 21.-24.09.2004, Erlangen, Germany, 2004)
LFT Import::2019-08-05 (1084)

Integrated Tube and Double Sheet Hydroforming Technology - Optimised Process for the Production of a Complex Part - Geiger, Manfred; Merklein, Marion; Cojutti, Massimo (Key Engineering Materials, 2007)
LFT Import::2019-07-16 (1399)
Keywords: Double sheet hydroforming; Process optimisation; Tube hydroforming

Integration of Double Sheet and Tube Hydroforming Processes: Numerical Investigation of the Feasibility of a complex Part - Geiger, Manfred; Cojutti, Massimo (The 23rd International Manufacturing Conference 30th August - 1st September 2006, University of Ulster, 2006)
LFT Import::2019-08-05 (1314)

Integration of Laser Material Processing into the Computer-Aided Product and Process Development - Geiger, Manfred; Kach, Andreas (3rd International Conference on Integrated Design and Manufacturing in Mechanical Engineering, 2000)
LFT Import::2019-08-05 (768)

Integrierte CAD/CAM-Systemgebung für die 3D-Laserstrahlbearbeitung von Leichtbaukomponenten - Kach, Andreas; Spitznagel, J. (Innovationen durch Laser Engineering II, 2000)
LFT Import::2019-07-15 (781)

Integrierte Fertigung durch Umformen, Fügen und Trennen - Merklein, Marion; Blankl, Andreas; Cojutti, Massimo (Arbeits- und Ergebnisbericht des DFG SFB 396, 2007)
LFT Import::2019-07-16 (1498)

Integrierte Fertigung durch Umformen, Trennen und Fügen in einem IHU-Werkzeug - Celeghini, Martino; Kreis, Oliver (Geschlossene Prozessketten vom Halbzeug zum Bauteil/ 8. Sächsische Fachtagung Umformtechnik 04.–05.11.2001, 2001)
LFT Import::2019-08-05 (853)

Integrierte Fertigung von tiefgezogenen Blechbauteilen mit Verzahnungselementen unter Einsatz von prozessangepassten Halbzeugen - Merklein, Marion; Behrens, B.-A.; Plettke, Raoul; Krimm, R.; Opel, Simon; Schneider, Thomas; Matthias, T.; Salfeld, V. (Tagungsband zum 1. Erlanger Workshop Blechmassivumformung 2011, 2011)
LFT Import::2019-08-05 (1765)

Integrierte Konstruktion und Fertigungsvorbereitung - Hoffmann, Peter; Greska, Wolfgang; Geiger, Manfred (Blech, Rohre, Profile, 1994)
LFT Import::2019-07-15 (616)

Integrierte Planung und Konstruktion von Werkzeugen für die Biegebearbeitung - Franke, Volker (Friedrich-Alexander-Universität Erlangen-Nürnberg, 1998)
The aim of the thesis was to reduce the user interactions needed for planning of bending sequences and to automise the process by taking into account standard and special bending tools. The work focused on the assignment of tools and the determination of toolsets, whereby design, production and administration of tools were considered as well. On the base of a knowledge based and self learning system for planning of bending sequences powerful concepts were developed in order to find optimal solutions in a short time. The technological assignment of tools for single bending sequences is done by the use of a fuzzy based system. So it was possible to implement expert rules for tool selection very simple. Tool design was automated with the aid of a neural network. The network application is divided into two different layers. In the first layer the tool type is selected by classifying the shape of the workpiece. In the second step the tool parameters are calculated with a network which takes into account the particular tool type. The planning system was completed with a rapid tooling system. The tools are constructed out of laser beam cut sheet metal lamellas. With the tool system it is possible to create new tools for complex bent components very rapidly and at low cost

Integriertes Bestück- und Laserstrahl-Lötsystem mit prozessbegleitender Qualitätssicherung - Geiger, Manfred; Feldmann, K.; Bickert, Matthias; Fröhlich, Thomas; Zolleis, B. (Produktionssysteme in der Elektronik - Sonderforschungsbereich 356 - Bericht des Forschungsverbundes 1999 - 2001, 2001)
LFT Import::2019-08-05 (864)

Intelligente Werkzeuge für das Kokillen- und Druckgießen- Teil 1: Prozesskettezur Werkzeugfertigung und Metallfolien-LOM-Technologie - Prechtl, Martin; Niebling, Frank; Otto, Andreas; Geiger, Manfred; Sobczyk, M.; Behm, I. (Giesserei, 2004)
LFT Import::2019-07-16 (1026)

Intelligente Werkzeuge für das Kokillen- und Druckgießen - Teil 2: Teilprozesse der Werkzeugfertigung und Versuche an Referenzteilen - Sobczyk, M.; Behm, I.; Prechtl, Martin; Saewert, H.C. (Giesserei, 2004)
LFT Import::2019-08-05 (1051)

Intelligente Werkzeuge für die wirtschaftliche Erzeugung seriennaher metallischer Prototypen und Kleinserien für das Kokillen- und Druckgießen - Behm, I.; Bähr, R.; Sobczyk, M.; Prechtl, Martin; Saewert, H.C.; Aliyev, R. (Giesserei, 2004)
LFT Import::2019-07-16 (1049)

Intelligent irradiation planning for new laser applications - Klämpfl, F.; Schmidt, Michael; Hagenah, Hinnerk (Proceedings of the 18th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM 2008), 2008)
LFT Import::2019-08-05 (258)

Intelligent Processing Head for CO2 Laser Material Processing - Geiger, Manfred; Neubauer, Norbert; Hoffmann, Peter (Production Engineering - Annals of the WGP, 1994)
LFT Import::2019-08-05 (600)

Interaction analysis of a notching and cyclic bending process - Biallas, Alina; Merklein, Marion (Manufacturing Letters, 2022)
The economic and ecological efficient production of steel wire fibers for reinforcing concrete is essential for exploiting their potential to reduce the required amount of building material. An innovative production process bases on the process chain notch rolling and cyclic bending. A sheet metal is notched on both sides and subsequently bent under undulated motion for causing a cyclic bending load in the formed notches. Due to damage effects during the cyclic bending, cracks initiate. The damage procedure and crack growth is influenced by the previous notched sheet called wire strip and the characteristics of the bending process. To analyze these effects, an influence and interaction study of the notches on the cyclic bending process is aspired. Based on a two-staged experimental design, the notching parameters notch tip radius and web height, which correlate with the amount of strain hardening, as well as the bending parameter bending angle, for identifying the interdependency of both processes, are evaluated. For study execution, an experimental model test for applying a cyclic bending load on a notched specimen is introduced.
Keywords: Metal forming; Cyclic bending; Damage