Methodology for the analysis of the process behaviour of advanced high strength steels in bending and shearing operations - Tsoupis, Ioannis; Hildering, Sven; Merklein, Marion (Key Engineering Materials, 2012)
In the automotive sector the application of advanced high strength steels (AHSS) for structural and safety relevant components plays an important role. Typical manufacturing processes concerning these parts are bending and cutting operations. However, the forming and cutting potential of these steel grades is different compared to conventional steels, as the process behaviour is changing. For an improved workpiece quality the fundamental knowledge of the damage and failure mechanisms is essential. This study presents a methodology for the analysis of AHSS in bending and out-of-plane shearing operations. Two micro alloyed high strength steels are investigated within this work. First results are presented concerning material characterisation by tensile tests, the material performance in air bending tests and the development of a modular punching tool. The study is closed by summarizing the damage behaviour along the process chain considering both bending and cutting. This shows the applicability of the presented methodology for analysing the process behaviour with respect to occurring failure.© (2012) Trans Tech Publications.
LFT Import::2019-07-29 (1781)
Keywords: Advanced high strength steel; Bending; Cutting; Damage

Methods for Determination of Residual Stress of a Formed Plate using Laser Ablation, Wire EDM and Milling - Lamsa, Janne; Mantyjarvi, Karl; Jarvenpaa, Antti; Grüner, Martin; Merklein, Marion; Karjalainen, Jussi A. (Key Engineering Materials, 2011)
In this work laser ablation was used for the determination of residual stress of a formed plate. Manufacturing processes, like bending, create residual stresses in the product and those can be very disadvantageous for fatigue durability. Residual stresses that are generated during the manufacturing of products can cause distortions, dimensional errors or can even break the products. The research material was ultra-high-strength steel (UHSS) with a yield strength of 1100 MPa. Specimens with a 90 degree bent angle were made by air bending using a press brake. Air bending causes variable residual stress patterns in the cross section of the material. The residual stresses of the formed area were determined by removing material and measuring strains caused by the release of stresses. A slot with the width of 1 mm has been manufactured parallel to the edge, both on the outer and on the inner side of the bend. True residual stress distribution can be calculated from the measured strains. A pumped 1064 nm Nd:YVO 4 ablation laser, whose pulse length is 90 ns, was used for the removal of material. This process creates a negligible heat affected zone (HAZ) and laser ablation doesn't increase stresses in the specimen. The results were compared with those obtained when slots were produced by milling and wire-EDM, as well as with the stress values measured by X-ray diffraction. © (2011) Trans Tech Publications.
LFT Import::2019-07-29 (1654)
Keywords: Bending; Laser ablation; Residual stress

Micro adjustment by laser ablation of prestressed coating layers - Eßer, Gerd; Dirscherl, Manfred (Proceedings of the 4th The Coatings 2004, 2004)
LFT Import::2019-08-05 (1040)

Micro-adjustment by thermally induced strains using laser technology - Huber, Alexander; Geiger, Manfred (Proceedings of the MICRO.tec 2000, VDE World Microtechnologies Congress, 2000)
LFT Import::2019-08-05 (780)

Micro-extrusion of an ultrafine grained copper can - Geißdörfer, Stefan; Rosochowski, A.; Olejnik, L.; Engel, Ulf (Proceedings of the 4th International Conference on Multi-Material Micro Manufacture, 2008)
LFT Import::2019-08-05 (1531)

Micro-extrusion of ultrafine grained copper - Geißdörfer, Stefan; Rosochowski, A.; Olejnik, Lech; Engel, Ulf; Richert, Maria Mr (Proceedings of the 11th International Esaform Conference on Material Forming, 2008)
Because of the well known virtues of low cost and high productivity, metal forming technology is well suited for mass production of metal micro-components. However, scaling down metal forming processes proves to be problematic because, among other factors, the relatively coarse grain (CG) structure of micro-billets leads to non-uniform material flow and lack of repeatability during microforming. A substantial grain size reduction below one micron should help to prevent these problems. The aim of the presented study is to investigate a possibility of using an ultrafine grained (UFG) metal for micro-extrusion. The material used for this purpose is CP Cu often used for electrical applications. The UFG version of Cu is produced by severe plastic deformation at room temperature using up to 8 passes of equal channel angular pressing. The microstructure and compression properties of the UFG version of the material are tested. The microforming process of backward extrusion is carried out at room temperature using half cylindrical billets. The extrusion force, grain flow, shape representation and surface quality of the extruded micro-components are compared. © 2008 Springer/ESAFORM.
LFT Import::2019-08-05 (1530)
Keywords: ECAP; In-situ process observation; Micro-extrusion; Ultrafine grained metal

Microfluid Devices Made by Automated Metal Foil LOM - Prechtl, Martin; Seidel, S.; Otto, Andreas; Roth, Stephan (4M 2005, Proceedings of the 1st International Conference on Multi-Material Micro Manufacture, 2005)
LFT Import::2019-08-05 (1146)

Microforming and investigation of parameter interactions - Eichenhüller, Bernd; Engel, Ulf; Geiger, Manfred (Production Engineering, 2010)
Microforming processes are significantly influenced by several process parameters. The research work covered in this paper investigates the interactions of some of these parameters and their impacts on the forming process. The impairment of formability and cavity filling are some typical results caused by miniaturizing the geometrical dimensions of the extruded form feature. The impact of an interaction on the forming result will be shown exemplarily with the temperature-pin diameter-interaction in more detail for a backward extrusion process. Additionally, the hardness distribution within the forming area will be investigated. © 2010 German Academic Society for Production Engineering (WGP).
LFT Import::2019-07-29 (313)
Keywords: Microforming; Production process; Size effect

Microforming - Application and 3D Simulation - Geißdörfer, Stefan; Diehl, Alexander; Eichenhüller, Bernd; Engel, Ulf (Proceedings of the 5th CIRP Seminar on Intelligent Computation in Manufacturing Engineering, 2006)
LFT Import::2019-08-05 (321)

Microforming at elevated temperature - forming and material behaviour - Eichenhüller, Bernd; Egerer, Emil; Engel, Ulf (International Journal of Advanced Manufacturing Technology, 2007)
Manufacturing of metallic parts by forming methods is industrially widespread due to several advantages like good surface quality, high accuracy and good efficiency at concurrent high quantity. As a result of the steady miniaturisation of products, large quantities of smallest metallic parts with the above mentioned attributes are needed. Despite the advantages of forming methods, microparts are mainly produced by machining, because of problems caused by so-called size-effects. These effects occur by scaling down geometry and process parameters, leading to the fact that the existing know-how for conventional processes cannot be transferred unrestrictedly to microscale. One reason for the difference between macro- and microscale is the number of grains within the forming area. At microscale only a small number of grains are directly involved in the forming process, so that the single grain, characterised by its individual size, orientation and position, gains influence on the process. The stochastic distribution of the grain characteristics leads to an inhomogeneous material behaviour and causes an increased scatter of the process parameters. To minimise the effect of inhomogeneous material behaviour, microforming at elevated temperature is applied. Experiments with different materials at elevated temperature show a homogenising effect which leads to a reduced process scattering. This indicates that elevated temperatures are suitable to minimise and control the size-effects at microforming processes. Additionally an enlargement of the forming limits by microforming at elevated temperature is observable. © Springer-Verlag London Limited 2007.
LFT Import::2019-07-15 (322)
Keywords: Microforming; Warm forming

Microforming - Geiger, Manfred; Kleiner, M.; Eckstein, Ralf; Tiesler, Nicolas; Engel, Ulf (Keynote Paper. Annals of the CIRP, 2001)
Microforming is a well suited technology to manufacture very small metallic parts, in particular for mass production, as they are required in many industrial products resulting from microtechnology. Compared to other manufacturing technologies microforming features specific economical and ecological advantages. Nevertheless, there are only some singular applications known until today. This paper tries to final out the reason why, analyzing systematically the problems emerging in transferring the know-how on forming from the macro- to the microworld. Reviewing the state of the art in basic and applied research reveals that scaling effects do appear not only within the process but must be taken into account in all the other areas of the whole forming system as well, demanding finally new solutions especially for tool manufacturing and machine concepts. Recent progress, innovative ideas and new developments on these sectors represent a promising basis to exploit the inherent potential of microforming in the future. © 2001 Elsevier Science Ltd. All rights reserved.
LFT Import::2019-08-05 (855)
Keywords: Equipment; Material; Micro Metal Forming

Microforming - Current State and Future Demands - Geißdörfer, Stefan; Putz, Alexander; Engel, Ulf (Journal of Mechanical Engineering, 2005)
LFT Import::2019-07-16 (1184)

Microforming - from basic research to its realisation - Engel, Ulf; Eckstein, Ralf (Journal of Materials Processing Technology, 2002)
The production of miniature parts is gaining importance due to the trend of miniaturization which is increasingly determining the development of products ranging from mobile phones and computers to medical products. The application of conventional manufacturing processes for the production of such microparts is possible, but there are problems that result from the small dimensions. This fact applies also in the field of metal forming, however, in the meantime many research projects in several countries could improve this situation. This paper gives a review of the problems associated with miniaturization, the way of solution starting from basic research, and the results showing the progress of microforming today. © 2002 Elsevier Science B.V. All rights reserved.
LFT Import::2019-07-16 (1677)
Keywords: Material behaviour; Micro-metal forming; Processes

Microforming of titanium - forming behaviour at elevated temperature - Eichenhüller, Bernd; Engel, Ulf (Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2008)
Titanium is applied in a wide range of technical applications, especially when high strength in combination with light weight or corrosion resistance is demanded. Titanium is also a popular material for implants in the field of medical technology due to its specific properties like the superb biocompatibility, the elastic behaviour matching that of the human bone, the radiological transparency, and the galvanic neutrality. For the production of microparts, e.g. small-sized implants, manufacturing methods with high accuracy and close tolerances are necessary. If forming processes are used to manufacture the miniaturized medical components, then the size effects occurring with miniaturization have to be considered. The size effects are, among others, responsible for an increased scatter of characteristic process outcomes and a reduced accuracy, thereby reducing the process stability. The limited formability of titanium and titanium alloys at room temperature is also a drawback of forming microparts made of titanium. The main objective of the present study is to investigate the forming behaviour of titanium at microscale and improve its formability by means of forming at elevated temperature.
LFT Import::2019-07-29 (323)
Keywords: Elevated temperature; Microforming; Titanium

Microforming - on the way to industrial application? - Engel, Ulf; Geißdörfer, Stefan (Proceedings of the 1st International Conference on Micromanufacturing, 2006)
LFT Import::2019-08-05 (1310)

Microforming Technology - History and Future - Engel, Ulf; Geißdörfer, Stefan (The 9th International Conference on Metal Forming ESAFORM, 2006)
LFT Import::2019-08-05 (1308)

Microlens laser beam homogenizer - From theory to application - Zimmermann, Maik; Lindlein, Norbert; Völkl, Ralf; Weible, Ken (Laser Beam Shaping VIII, 2007)
Many applications in laser manufacturing like semiconductor lithography, micro-machining, micro-structuring or material-analysis require a homogeneous intensity distribution of the laser beam over its complete profile. Refractive and diffractive beam homogenizer solutions have been developed for this challenge, but their applicability strongly depends on the physics of the individual laser beam. This paper investigates the influence of laser beam properties like spatial coherence for microlens beam homogenizers. Diffraction at the small lens apertures and interference effects of periodic arrays are explained by using diffraction theory. Different microlens beam homogenizer configurations are presented. Design considerations that might be helpful for the layout of a specific microlens beam homogenizer system are discussed. It is shown that, among other factors, the Fresnel number is the most important quantity to characterize the influence of diffraction effects on microlens laser beam homogenizers. The influence of the spatial partial coherence will be explained for the example of a Fly's eye condenser. For cw laser sources, the influence of a rotating diffuser plate on grating interference and speckles effects is investigated. Finally, the theory will be compared to some practical examples in planar laser measurement techniques, in combustion diagnostics and micromachining with Excimer laser
LFT Import::2019-08-05 (1478)
Keywords: Coherence; Diffraction; Diffuser; Flat-top; Homogenizer; Laser; Microlens; Shaping

Micromachining of Ceramics with Excimer Laser Radiation - Goller, M.; Lutz, Norbert; Geiger, Manfred (Journal of the European Ceramic Society, 1993)
A XeCl excimer laser (λ = 308 nm) was used for investigating the possibilities of micromachining ceramic materials. The influence of the optical setup and laser parameters on the processing quality has been determined, as well as the behaviour of various ceramic materials during the machining process. The machining results and the structure quality are discussed concerning the shape of the holes, break-outs in the structure and the homogeneity of the hole depth and size. Optical microscopy and SEM investigations served as the main tools for the characterization. Strategies for large area micromachining were investigated to achieve a very large number of high quality microstructures. © 1993.
LFT Import::2019-07-15 (416)

Micromechanisms of Cortical Bone Failure under Different Loading Conditions - Sharma, N. K.; Sharma, Swati; Rathi, Apoorv; Kumar, Abhinav; Saini, Karan Vir; Sarker, M. D.; Naghieh, Saman; Ning, Liqun; Chen, Xiongbiao (Journal of Biomechanical Engineering-Transactions of the Asme, 2020)
Bone being a hierarchical composite material has a structure varying from macro- to nanoscale. The arrangement of the components of bone material and the bonding between fibers and matrix gives rise to its unique material properties. In this study, the micromechanisms of cortical bone failure were examined under different loading conditions using scanning electron microscopy. The experimental tests were conducted in longitudinal and transverse directions of bone diaphysis under tensile as well as compressive loading. The results show that bone material has maximum stiffness under longitudinal tensile loading, while the strength is higher under transverse compressive loading. A reverse trend of compressive mechanical properties of bone is observed for longitudinal and transverse loading as compared to trends reported in the previous studies. Therefore, micromechanisms of cortical bone failure were analyzed for different loading conditions to reveal such type of behavior of cortical bone and to correlate bone microstructure with mechanical response of bone.
CRIS-Team Scopus Importer:2020-08-28
Keywords: bone; compressive loading; micromechanism; SEM; tensile loading

Micro-optical rotary joint for multichannel communication via rotaring interface - Schmidt, Michael; Rank, M.; Stark, Markus; Eßer, Gerd (Proceedings of the Photonics West 2005, 22.-27.01., San Jose, Kaliforniern, USA, 2005)
LFT Import::2019-08-05 (1230)

Microoptics for Laser Beam Homogenizing and Beam Shaping - Völkl, Ralf; Bich, A.; Eisner, M.; Weible, K.J.; Zimmermann, M.; Rank, M. (Proceedings of the 5th International Conference on Laser Assisted Net Shape Engineering, 2007)
LFT Import::2019-08-05 (1476)

Microparts - a challenge for forming technology - Engel, Ulf; Tiesler, Nicolas; Eckstein, Ralf (Conference Proceedings ICIT 2001 3rd International Conference on Industrial Tools, Rogaska Slatina, Slovenia, April 22nd-26th, 2001)
LFT Import::2019-08-05 (844)

Micro Production - Chances and Challenges - Geiger, Manfred; Eßer, Gerd (Proceedings of the 3rd ISPF-Seminar, 2004)
LFT Import::2019-08-05 (1104)

Microstructural evolution and geometrical properties of TiB2 metal matrix composite protrusions on hot work tool steel surfaces manufactured by laser implantation - Spranger, Felix; de Oliveira Lopes, Marcelo; Schirdewahn, Stephan; Degner, Julia; Merklein, Marion; Hilgenberg, Kai (International Journal of Advanced Manufacturing Technology, 2019)
The laser implantation–named technique aims to address the tribological problems frequently seen on tool surfaces during hot stamping. It is based on the creation of elevated dome- or ring-shaped hard structures on the surface of tool steels by a localized dispersing of hard particles. Therefore, a combination of the two distinct approaches that are normally used in surface technology for optimizing friction and wear, i.e., surface texturing and surface material optimization, are realized in one processing step. In experimental studies, a localized dispersing of TiB2 particles in the surface layer of the hot work tool steel X38CrMoV5-3 was considered and compared with punctual laser–remelted textures. The structures (micro-) hardness was measured at top- and cross-sections. With the aid of a scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction the interaction between the hard particles and the substrate material were studied. From the results, an optimal parameter range was identified for laser implantation. To the investigation’s end, the implant geometry was measured by optical microscopy and white light microscopy. Furthermore, a mathematic model was introduced, which allows a prediction of the implant geometry as a response to the laser parameters. It was shown that the implantation of TiB2 particles leads to a significant hardness increase up to 1600 HV1 due to the dispersion of initial particles and an in situ precipitation of new titanium-rich phases. It was possible to create defect-free dome- and ring-shaped microstructures on the surfaces. It was also shown that the implants geometry highly depends on the applied laser parameters. The applied central composite design shows a good agreement with the experimental results.
CRIS-Team Scopus Importer:2019-12-03
Keywords: Hot stamping; Hot work tool steel; Laser implantation; Localized laser dispersing; Surface texturing; TiB2

Microstructural Investigations of Aluminium Tailored Heat Treated Blanks - Geiger, Manfred; Merklein, Marion; Kerausch, Michael (Production Engineering. Annals of the German Academic Society for Production Engineering WGP, 2004)
LFT Import::2019-08-05 (1094)

Microstructured surfaces in highly loaded EHD-contacts - manufacturing and tribological performance - Schrader, Tobias; Weschta, Martin; Engel, Ulf; Tremmel, Stephan; Merklein, Marion; Wartzack, Sandro (Proc. 10th International Conference THE "A" Coatings in Manufacturing Engineering, 2013)
In low loaded sliding contacts, as journal bearings or piston contacts, defined microstructures on surfaces were identified for friction reduction purposes and are well established in industrial applications. It is stated that microstructures act as lubricant reservoirs and support lubricant film development. Within the scope of these investigations microstructures are specifically adapted for the tribological load collective of cam follower systems as a representative of highly loaded contacts. For those contacts, the effects of microstructures are still subject of investigations. In this paper a method for efficient microstructuring by micro laser ablation is described. The investigations focus on the determination of the geometric and mechanical properties of the microstructures as well as on the tribological behavior of the microstructured surfaces by two tribological tests.
UnivIS-Import:2015-04-16:Pub.2013.tech.FT.FT-KLMEFK.micros_0

Microstructured surfaces in highly loaded elastohydrodynamic (EHD)-contacts - manufacturing and tribological performance - Schrader, Tobias; Weschta, Martin; Engel, Ulf; Tremmel, Stephan; Merklein, Marion; Wartzack, Sandro (Materialwissenschaft und Werkstofftechnik, 2013)
In low loaded sliding contacts, as journal bearings or piston contacts, defined microstructures on surfaces were identified for friction reduction purposes and are well established in industrial applications. It is stated that microstructures act as lubricant reservoirs and support lubricant film development. Within the scope of these investigations microstructures are specifically adapted for the tribological load collective of cam follower systems as a representative of highly loaded contacts. For those contacts, the effects of microstructures are still subject of investigations. In this paper a method for efficient microstructuring by micro laser ablation is described. The investigations focus on the determination of the geometric and mechanical properties of the microstructures as well as on the tribological behavior of the microstructured surfaces by two tribological tests.
UnivIS-Import:2015-03-09:Pub.2013.tech.FT.FT-KLMEFK.micros_6
Keywords: EHD-Kontakt; Mikrolaserablation; Mikrostrukturen; Reibversuche; Tribologie

Micro Texturing of Ceramic Tool Surfaces and its Influence on Friction in Sheet Metal Forming Processes - Geiger, Manfred; Neudecker, Thomas; Engel, Ulf (Production Engineering, 2000)
LFT Import::2019-07-15 (808)

Micro Texturing of Cold Forging Tools - Influence on Tool Life - Popp, Uwe; Engel, Ulf (Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2006)
LFT Import::2019-07-16 (1280)

Micro Texturing of Tool Surfaces and its Influence on Friction in Deep Drawing Processes - Neudecker, Thomas; Popp, Uwe; Engel, Ulf; Geiger, Manfred (Proceedings of the 8th International Conference on Sheet Metal, 2000)
LFT Import::2019-08-07 (794)

Micro Texturing of Tool Surfaces and its Influence on Friction in Forming Processes - Neudecker, Thomas; Popp, Uwe; Engel, Ulf; Geiger, Manfred (X. International Colloquium on Surfaces, 2000)
LFT Import::2019-08-05 (793)

Mikrobiegen und Präzisionsrichten mit gepulster UV-Laserstrahlung. - Geiger, Manfred; Becker, Wolfgang; Vollertsen, Frank (Laser und Optoelektronik, 1997)
LFT Import::2019-07-15 (714)

Mikrojustierung mit Licht - Zimmermann, M.; Dirscherl, Manfred (Mikroproduktion, 2006)
LFT Import::2019-07-16 (1295)

Mikrooptiken für die effiziente Materialbearbeitung mit Excimerlasern. - Hutfless, Joachim; Rebhan, Thomas; Lutz, Norbert; Geiger, Manfred; Frank, M.; Streibl, N.; Schwinder, J. (Laser und Optoelektronik, 1994)
LFT Import::2019-07-15 (619)

Mikrooptischer Drehübertrager - Popp, Uwe; Stark, Markus; Rank, M.; Poisel, H. (Tagungsband des Internationales Forum Mechatronik, Augsburg, Juni, 2005)
LFT Import::2019-08-05 (1232)

Mikroproduktion? Chancen und Herausforderung - Geiger, Manfred; Geißdörfer, Stefan (22. ASK, Aachener Stahlkolloquium, 2007)
LFT Import::2019-08-05 (1419)

Mikroproduktionstechnik: Chance und Herausforderung für die Lasertechnik - Geiger, Manfred; Eßer, Gerd (Tagungsband Stuttgarter Lasertage 2003, 2003)
LFT Import::2019-08-05 (987)

Mikroproduktionstechnik: Minibauteile mit Größe - Geiger, Manfred; Eßer, Gerd (Zukunft im Brennpunkt, 2003)
LFT Import::2019-07-15 (982)

Mikroproduktionstechnik-Schlüsseltechnologie für die Produktion von morgen? - Eckstein, Ralf (Tagungsband der Herbsttagung 2002 des Instituts für Werkzeugmaschinen und Betriebstechnik, 2002)
LFT Import::2019-08-05 (1695)

Mikro-Schockwellen durch Ultrakurzpuls-Interaktion als neuartiger Mechanismus für ein hochgenaues Laserstrahljustierverfahren - Schmidt, Michael; Dirscherl, Manfred (Verhandlungen der Deutschen Physikalischen Gesellschaft zur DPG-Frühjahrstagung, 2006)
LFT Import::2019-08-05 (1273)

Mikrostanzen - Einsatz von einkristallinem Silizium als Werkzeugwerkstoff für Schneidprozesse von dünnen Folien - Becsi, L.; Hildering, Sven; Mescheder, U.; Engel, Ulf (Tagungsband 4. Mikrosystemtechnik-Kongress Darmstadt, 2011)
LFT Import::2019-08-05 (1751)

Mikrostrukturelle und mechanisch-technologische Eigenschaften widerstandspunktgeschweißter Aluminium-Stahl-Verbindungen für den Fahrzeugbau - Neudel, Christian (2014)
The scope of this thesis was resistance spot welding of aluminum to steel caused by new material concepts with elevated strengths, which are critical for mechanical joining technologies. In addition spot welding is an economic joining technology due to the short process time and favorable manufacturing equipment. The welding parameters and machine parts were varied systematically to adjust reproducible joining characteristics and force the intermetallic phases to grow in a specifically rang

Mikrostrukturierung von Tassenstößeln zur Reibungsreduzierung im Ventiltrieb – Herstellung, Simulation und tribologische Charakterisierung - Weschta, Martin; Schrader, Tobias; Tremmel, Stephan; Merklein, Marion; Wartzack, Sandro; Engel, Ulf (Tribologie und Schmierungstechnik, 2014)
Im Rahmen der in einem Verbundprojekt durchgeführten Untersuchungen wurden Mikrostrukturen mit dem Ziel der Reibungsreduzierung speziell an das tribologische System eines Nocken/Stößel-Kontaktes, als Beispiel für hochbelastete Wälz-Gleit-Kontakte, angepasst. Für diese Art von Reibkontakten sind die Effekte von Mikrostrukturen noch nicht abschließend geklärt. Zur Erlangung disziplinübergreifender Erkenntnisse wurden Mikrostrukturformen durch numerische Simulationen ausgelegt sowie die Genauigkeit der Fertigung und das tribologische Verhalten der mikrostrukturierten Komponenten untersucht. Für die Herstellung der Mikrostrukturen wurde aufgrund der Perspektive für die Großserienanwendung auf den Prozess des Mikroprägens fokussiert, der der Mikrolaserablation hinsichtlich seiner Genauigkeit gegenübergestellt wurde. Für die mikrostrukturierten Ventiltassenoberflächen wurde im Prüfstand eine signifikante Reibungsreduzierung gegenüber polierten Oberflächen erreicht.
LFT Import::2019-07-29 (1977)

Mikrostrukturierung von Tassenstößeln zur Reibungsreduzierung im Ventiltrieb - Herstellung, Simulation und tribologische Charakterisierung - Weschta, Martin; Schrader, Tobias; Tremmel, Stephan; Merklein, Marion; Wartzack, Sandro; Engel, Ulf (54. Tribologie-Fachtagung. Reibung, Schmierung und Verschleiß. Band II, 2013)
Im Rahmen der in einem Verbundprojekt durchgeführten Untersuchungen wurden Mikrostrukturen mit dem Ziel der Reibungsreduzierung speziell an das tribologische System eines Nocken-Stößel-Kontaktes, als Beispiel für hochbelastete Wälz-Gleit-Kontakte, angepasst. Für diese Art von Reibkontakten sind die Effekte von Mikrostrukturen noch nicht abschließend geklärt. Zur Erlangung disziplinübergreifender Erkenntnisse wurden Mikrostrukturformen durch numerische Simulationen ausgelegt sowie die Genauigkeit der Fertigung und das tribologische Verhalten der mikrostrukturierten Komponenten untersucht. Die tribologische Wirkung der Mikrostrukturen wurde in einem zweidimensionalen elastohydrodynamischen Simulationsmodell bestimmt. Für die Herstellung der Mikrostrukturen wurde aufgrund der Perspektive zur Großserienanwendung auf den Prozess des Mikroprägens fokussiert, der der Mikrolaserablation hinsichtlich seiner Genauigkeit gegenübergestellt wurde. Für die mikrostrukturierten Ventiltassenoberflächen wurde im Prüfstand eine signifikante Reibungsreduzierung gegenüber polierten Oberflächen erreicht.
UnivIS-Import:2015-04-16:Pub.2013.tech.FT.FT-KLMEFK.mikros

Miniaturization in sheet metal working - Kals, Roland; Eckstein, Ralf (Journal of Materials Processing Technology, 2000)
Miniaturization of sheet metal working processes causes changes in the relative contribution of relevant process parameters. As a result, so-called second-order size effects occur. The present paper should give a survey of different kinds of second-order size effects that can be expected in tensile testing, air bending and punching of sheet metal. These size effects show to be commensurable when the process conditions are similar to a certain amount, as it is the case for tensile testing and air bending. However, they change or even diminish when the process conditions are very different, as for example in punching.
LFT Import::2019-07-15 (782)

Mittels Laserstrahljustiersintern von PEEK zu echten Funktionsprototypen - Rechtenwald, T.; Roth, Stephan; Pohle, D. (Tagungsband der Tagung Laser in der Elektronikproduktion & Feinwerktechnik, 2006)
LFT Import::2019-08-05 (1284)

Modeling Laser Heating for Roller Hemming Applications - Kleeh, Tobias; Merklein, Marion; Roll, Karl (Key Engineering Materials, 2011)
LFT Import::2019-07-29 (1694)
Keywords: FEM; Heat treatment; Roller hemming

Modeling material behavior of AA5083 aluminum alloy sheet using biaxial tensile tests and its application in numerical simulation of deep drawing - Prakash, Ved; Kumar, D. Ravi; Horn, Alexander; Hagenah, Hinnerk; Merklein, Marion (International Journal of Advanced Manufacturing Technology, 2020)
Improvement in accuracy of the predicted results from numerical simulation results into a reduction of cost and time involved in tool design and experimental trials. However, the predicted results from finite element simulations are significantly affected by the chosen yield criterion and work hardening law. The selection of yield criterion and work hardening law depends on the characterization methods used for defining the material behavior. In this work, the mechanical behavior of AA5083-O aluminum alloy sheet is modeled by performing biaxial tensile tests using cruciform specimen and hydraulic bulging experiments in addition to uniaxial tensile tests. Biaxial to uniaxial yield stress ratios are determined using the equal plastic work principle from the flow curves obtained from these tests. The obtained ratios are used to find the coefficients of Yld2000-2d and Hill48 yield criteria which is then used in the numerical simulations of cylindrical cup deep drawing. Numerical simulations are also carried out using uniaxial and biaxial flow curves fitted with different isotropic hardening laws. Thickness distributions and the load-displacement curves are predicted and validated by performing cylindrical cup deep drawing experiments.
CRIS-Team Scopus Importer:2019-12-17
Keywords: Aluminum alloy; Cruciform specimen; Deep drawing; Finite element simulation; Hardening laws; Hydraulic bulge test; Yield criteria

Modeling of Process-Tool-Machine Interactions in Cold Forging - Kroiß, Thomas; Völkl, Ralf; Engel, Ulf; Geiger, Manfred (Proc. 1st Int. Conf. on Process Machine Interactions (PMI), 2008)
LFT Import::2019-08-05 (496)

Modeling of the Behavior of a Cold Forging Process Considering the Deflection of Tooling System and Press - Kroiss, Thomas; Engel, Ulf; Merklein, Marion (Proc. 2nd Int. Conf. on Process Machine Interactions (PMI), 2010)
LFT Import::2019-08-05 (500)

Modeling of the Material Behaviour of Magnesium Alloy AZ31 Using Different Yield Criteria - Banabic, Dorel; Hußnätter, Wolfgang (International Journal of Advanced Manufacturing Technology, 2009)
Nowadays, the finite element analysis (FEA) is playing a main rule in fields of sheet metal forming for designing processes and dimensioning parts. The most frequent yield criteria used in the FE commercial programs for the sheet-metal-forming simulation, like AUTOFORM, PAMSTAMP, etc., are Hill'48 for common steels or Barlat'89 and various BBC models for some aluminum alloys. In this paper, different yield loci for biaxial tensile stress conditions of the magnesium sheet metal alloy AZ31 are investigated. The experimental investigations have been done using the specimen geometry for the experimental setup developed at the Chair of Manufacturing Technology (LFT) of the University of Erlangen. The yielding behavior is determined basing exclusively on real material data out of experiments so that no FE calculations are necessary to detect strains and stresses. Using these data, several yield criteria are applied to approximate the real material characteristics, whereas the model of BBC'2005 leads to the best agreement for uniaxial yield stresses, the anisotropy coefficients, and the yield locus. © 2009 Springer-Verlag London Limited.
LFT Import::2019-07-29 (1569)
Keywords: BBC'2005; Material characterization; Yield criterion; Yield locus diagram

Modeling of the Plastic Characteristics of AA6082 for the Friction Stir Welding Process - Pellegrino, Sergio; Fratini, Livan; Merklein, Marion; Böhm, Wolfgang; Hung Nguyen, (Key Engineering Materials, 2015)
Focus of this paper is to model the plastic forming behavior of AA6082, in order to develop the numerical FE analysis of the friction stir welding processes and the simulation of subsequent forming processes. During the friction stir welding process, the temperatures reached can range up to 500 °C and have a fundamental role for the correct performance of the process, so the material data has to show a temperature dependency. Because of the tool rotation a strain rate sensitivity of the material has to be respected as well. In this context, the general material characteristics of AA6082 were first identified for different stress states. For the uniaxial state the standard PuD-Al used in the automotive industry was applied, for the shear state the ASTM B831-05 was used and for biaxial states the ISO 16842 was exploited. To characterize the plastic flow behavior of the AA6082 at elevated temperatures, tensile tests were performed according to DIN EN ISO 6892-2 from 25 °C to 500 °C with a strain rate from 0.1 s-1 up to 6.5 s-1.
EAM Import::2019-03-12

Modellbasierte Prozessauslegung für die Kaltmassivumformung unter Brücksichtigung der Werkzeug- und Pressenauffederung - Kroiß, Thomas (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2012)
Within the investigations, an analytic model was developed for common cold forging processes that represents the workpiece dimensions depending on several influencing parameters in consideration of the interactions between process, tooling system and press. lt enables an automated optimization of different setting parameters to ensure high workpiece accuracy. Moreover, the model permits an estimate of achievable tolerance range

Modellbasierte Prozesskettenabbildung rührreibgeschweißter Aluminiumhalbzeuge zur umformtechnischen Herstellung höchstfester Leichtbaustrukturteile - Gnibl, Tobias (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2019)
A key factor for an efficiency increase in air plane and space ship manufacturing is the development of technologies for cost and resource efficient production of structural parts. High strength aluminum alloys show a high potential for the use in aerospace applications, nevertheless innovations are limited by the state of the art of shaping technologies. An advanced approach is to form large scale spherical parts from tailor welded blanks. Therefor it is essential to have the knowledge about the interactions along the process chain and be able to calculate their influence on final part properties and quality. Within this scientific work specific material characterization provides the basis for the understanding of heat treatment, forming and joining technology. Furthermore, to be able to fulfill multi criteria specifications in part and process design a methodology based on analytical and numerical models has been introduced and verified according its general applicability for the manufacturing of light-weight structural parts made of high strength aluminu

Modellierung des Verfestigungsverhaltens von Blechwerkstoffen - Merklein, Marion; Biasutti, Manfredi; Lupino, Roberto; Kuppert, Andreas (13. Workshop - Simulation in der Umformtechnik (19.03.2010), 2010)
LFT Import::2019-08-05 (201)

Modellierung und Simulation der Warmblechumformung: Aktueller Stand und zukünftiger Forschungsbedarf - Brosius, A.; Karbasian, H.; Tekkaya, A.E.; Lechler, Jürgen; Merklein, Marion; Geiger, Manfred; Springer, R.; Schaper, M.; Bach, F.W.; Hoffmann, H. (Tagungsband 2. Erlanger Workshop Warmblechumformung, 2007)
LFT Import::2019-08-05 (1499)

Modellierung von Aktoren für das Laserstrahljustieren in der Mikrotechnik - Geiger, Manfred; Wurm, Thomas; Hagenah, Hinnerk (Fortschritte in der Simulationstechnik, Tagungsband des 17. Symposiums Simulationstechnik ASIM 2003, 2003)
LFT Import::2019-08-05 (943)

Modelling and experimental study of a microforging process from metal strip for the reduction of defects in mass production - Stellin, Tommaso; Van Tijum, Redmer; Engel, Ulf (Production Engineering, 2016)
Microforming from sheet metals is a technology with high potential and increasing interest in modern factories. The combination of bulk forming technologies in micro-scale together with the easier handling of metal strips allows the high rate production of products with small dimension and is suited for commercial fields like electronics and micromechanics. The need of an efficient FEM aided process design must face the problem of material behavior in microforming, affected by size-effects and not obeying continuum mechanics. A reliable FE model allows the production of a database allowing, additional to process optimization, the design of online process control and the reduction of manufacturing defects, strongly affecting micro-productions because of the high deviations in such processes. In this work, a method for the design of a FEM model of a microforging process is proposed, developed in the commercial software MSC Marc including the modelling of local size effects in the form of variable friction. An increased friction factor is assumed, where typical microforming size effects are expected to take place. Stainless steel and copper-beryllium alloys are studied with the thickness of 300 µm. The microforged geometry consists in 6 parallel protrusions with a width of 200 µm. The experimental study is then performed, by varying punch forces, firstly in a simplified configuration with two protrusions and finally with the complete geometry in a multi-stage microforming process, respectively validating and verifying the developed simulation model.
LFT Import::2019-07-29 (2163)
Keywords: Copper-beryllium; Microforming; Numerical simulation; Sheet-bulk forming; Stainless steel

Modelling and Simulation of Piezoelectric Actuation and Reliability of Micropumps - Zhu, M.; Kirby, P.B.; Richter, M.; Congar, Y.; Diehl, Alexander; Völkl, Ralf (4M 2006, 2nd International Conference on Multi-Material Micro Manufacture, 20.-22.09.2006, Grenoble, France, 2006)
LFT Import::2019-08-05 (1322)

Modelling Aspects in Accumulative Roll Bonding Process by Explicit Finite Element Analysis - Fratini, Livan; Merklein, Marion; Böhm, Wolfgang; Campanella, Davide (Key Engineering Materials, 2013)
Accumulative Roll-Bonding (ARB) process is a severe plastic deformation (SPD) process, capable of developing grains below 1 extgreekmm in diameter and improving mechanical properties of the material. In this study, the authors compared two different FE-codes with respect of its applicability for numerical analysis of the ARB process. Modelling this process was achieved using the explicit code for Abaqus/CAE both in 2D and 3D. The proposed model was used to assess the impact of ARB cycles on the final material properties. The numerical results in 2D and 3D were compared and contrasted. The research work presented in this paper is focused on the simulation optimization based on CPU time minimization. The numerical simulations were also validated through a comparison with the experimental results.
EAM Import::2019-03-12

Modelling, Construction and Manufacture of a Lightweight Robot Arm - Hagenah, Hinnerk; Böhm, Wolfgang; Breitsprecher, Thilo; Merklein, Marion; Wartzack, Sandro (Proceedings of the 8th CIRP International Conference on Intelligent Computation in Manufacturing Engineering, 2012)
This contribution will show how modern materials as cellular titanium and nanocrystalline aluminium can be used to build advanced lightweight robot arms. Cellular titanium allowing a specific density distribution and the manufacture of fine structures with desirable properties is produced by selective electron beam melting while the nanocrystalline aluminium results from accumulative roll bonding. The specific properties of both materials will be highlighted. The paper will cover the definition of the product specification, the setting of a basic design and the optimisation of this by means of topology optimisation. This optimisation requires an intelligent modelling to be able to investigate different initial settings and boundary conditions. The optimised part will then be finished with regards to manufacturability. The paper will close with a brief report about the actual manufacture of one of the investigated variants.
UnivIS-Import:2015-04-16:Pub.2012.tech.FT.FT-KLMEFK.modell

Modelling kinetics of phase transformation for the indirect hot stamping process - Hippchen, Paul; Merklein, Marion; Lipp, Arnulf; Fleischer, Michael; Grass, Hannes; Philipp, Craighero (Key Engineering Materials, 2013)
To configure the indirect hot stamping process, a finite-element-based prediction of the part's geometry and mechanical properties is required. In case of indirect hot stamping, inhomogeneous cooling schedules cause different phase transformation points and products. The volume expansion caused by phase transformation of fcc into bcc leads to transformation induced stresses that are important for the calculation of overall stresses in press hardened components. To calculate theses stresses correctly, it is necessary to study the kinetics of phase transformation in consideration of the cooling path of an indirect hot stamping process. Dilatometer tests are employed to obtain the kinetics of phase transformation is determined in dilatometer tests. These results are used to identify the parameters for the phase transformation models implemented in the material model *MAT-244 [1] that is implemented in the finite-element-code LS-DYNA [2]. In this context the material model parameters are identified by using evolutionary optimization strategies. Based on the identified parameters the predictive quality of the implemented phase transformation models will be studied in order to improve their prediction accuracy for the indirect hot stamping process. © (2013) Trans Tech Publications.
LFT Import::2019-07-29 (2072)
Keywords: Hot stamping; Kinetics of phase transformation; LS-DYNA; Simulation

Modelling kinetics of phase transformation for the indirect hot stamping process to focus on car body parts with tailored properties - Hippchen, Paul; Lipp, Arnulf; Grass, Hannes; Craighero, Philipp; Fleischer, Michael; Merklein, Marion (Journal of Materials Processing Technology, 2015)
LFT Import::2019-07-29 (2071)

Modelling of a Flexbile Tube Bending Technology Using an Elastomere Tool - Nock, Marco; Geiger, Manfred (COMA 2004, Proceedings of the International Conference on Competetive Manufacturing, Stellenbisch, South Africa, 2004)
LFT Import::2019-08-05 (1046)

Modelling of Hybrid Parts Made of Ti-6Al-4V Sheets and Additive Manufactured Structures - Hafenecker, Jan; Papke, Thomas; Huber, Florian; Schmidt, Michael; Merklein, Marion (Proceedings of the 10th Congress of the German Academic Association for Production Technology (WGP), 2020)
Keywords: Additive Manufacturing; Forming; Titanium.

Modelling of Laser Beam Welding at 3D Workpiece Contours. - Otto, Andreas; Backes, Frank; Geiger, Manfred (Proceedings of the 6th European Conference on Laser Treatment of Materials, ECLAT 96, 1996)
LFT Import::2019-08-05 (664)

Modelling the deep drawing of process optimized blanks - Vollertsen, Frank; Hofmann, Achim (Proceedings of the 20th Biennal IDDRG Congress, 2000)
LFT Import::2019-08-05 (1623)

Modification of Ceramic Surfaces by Excimer Laser Processing - Becker, Wolfgang; Hutfless, Joachim; Geiger, Manfred (Cleo/Europe 94 Conference Proceedings, 1994)
Excimer laser radiation was found to be applicable in modifying ceramic surfaces. This technique proves to be novel, flexible and effective alternative to traditional modes of surface finishing of ceramics with costly diamond equipment. In this study, a XeCl excimer laser was applied to smooth alumina and silicon carbide ceramics. Basic testings were carried out to obtain data with regard to interaction mechanisms and to determine the optical processing parameters. Meanwhile, strength and wear experiments are designated to characterize the mechanical and tribological features of the processed surfaces.
LFT Import::2019-08-05 (631)

Modification of Tribological Conditions for Influencing the Material Flow in Bulk Forming of Microparts from Sheet Metal - Kraus, Martin; Andreas, Kolja; Stellin, Tommaso; Engel, Ulf; Merklein, Marion (AIP Conference Proceedings 1896, 2017)
LFT Import::2019-08-05 (2269)

Montagequalität von armierten Werkzeugen - Putz, Alexander (Produktion, 2006)
LFT Import::2019-07-16 (1315)

MoS2-Alloyed Steel for Wear-Loaded Parts - Vollertsen, Frank; Geiger, Manfred (Proc. of PM´94 World Congress, Editions de Physique I, Paris, 1994)
LFT Import::2019-07-15 (626)

Multifractal spectrum of a laser beam melt ablation process - Neto, C.R.; Bube, K.; Cser, Adrienn Orsolya; Otto, Andreas; Feudel, U. (Physica A-Statistical Mechanics and Its Applications, 2004)
The surface profiles resulting from a laser beam melt ablation process have been quantified on the basis of the multifractal formalism. The multifractal spectra for several parameters sets, obtained with the wavelet transform modulus maxima method, were found to change towards higher Hölder exponents as the system undergoes a regime transition from medium to high ablation rates. This is consistent with the experimental observation of pattern formation at high ablation rates. © 2004 Elsevier B.V. All rights reserved.
LFT Import::2019-07-16 (1098)
Keywords: Laser beam machining; Multifractal spectrum; Pattern formation; Wavelet transform

Multi-Objective Optimization of Actuator System Design for Laser Micro Adjustment - Geiger, Manfred; Plettke, Raoul; Hagenah, Hinnerk (Production Engineering, 2009)
Complex design processes require a high level of expertise and are time consuming. By assisting the engineer with a computer aided design system the design process can be accelerated and be made more reliable. Actuator system design for laser micro adjustment is complex and its challenges may be a hindrance for the application of laser micro adjustment. To overcome this obstacle a computer aided design system was developed which utilizes a multi-objective optimization algorithm to automatically improve actuator design. In this paper, the system and its components are presented. A special focus will be upon the assessment functions which allow the efficient assessment of an actuator design. An application example will be given to demonstrate the functionality of the design system. © German Academic Society for Production Engineering (WGP) 2008.
LFT Import::2019-07-29 (147)
Keywords: Computer aided design; Laser micro adjustment; Multi-objective optimization

Nachhaltige Blechumformung durch Trockentiefziehen - Krachenfels, Kim; Tenner, Jennifer; Merklein, Marion (wt Werkstattstechnik - Online, 2018)
Werkstattstechnik online 108 (2018), S. 652-656
LFT Import::2019-07-29 (2328)

Nachhaltige Umformtechnik - Merklein, Marion (VDI-Z Integrierte Produktion, 2023)
CRIS-Team Scopus Importer:2023-03-24

Nanotopography characterisation in microforming - Weidel, Stephan; Engel, Ulf; Geiger, Manfred (Proceedings of the 7th International Conference of the European Society for Precision Engineering and Nanotechnology Euspen, Bremen, 2007)
In microforming applications the contact state between the tool and a lubricated workpiece differs significantly from that of a forming process in conventional length scale. The drastic reduction of the lateral dimensions of the workpiece surfaces in microforming, while there is no change in surface roughness, causes a significant reduction of the number of asperities contacting the tool. Therefore, the influence of single asperities on the tribological behaviour of the surface increases. Thus, the assumption that a complete flattening of the regions on top of the asperities contacting the tool takes place during forming can not be maintained. Instead, the socalled nanotopography on top of the flattened asperities has to be investigated. The relationship between these contact regions, the lubricant and the impact on the tribological behaviour has not been analysed yet. In this paper the flattening behaviour of single idealised asperities is analysed. A test rig for surface flattening is introduced, which enables the in-situ observation of the developing contact area with a translucent tool, a telecentric objective and a CCDcamera. Upsetting tests are performed with and without lubricant. The nanotopography and its behaviour during flattening is characterised by confocal microscopy and scanning probe microscopy.
LFT Import::2019-08-05 (1404)

Neue Entwicklungen bei IHU von Blechen und deren Einsatzpotenziale für Leichtbauteile - Geiger, Manfred; Merklein, Marion; Celeghini, Martino; Novotny, Stefan; Vahl, Meik (Innenhochdruck-Umformen für Karosseriekomponenten, 2002)
LFT Import::2019-07-16 (1706)

Neue Erkenntnisse zum Laserstrahlschneiden: Durch Experimente zu höherer Flexibilität - Geiger, Manfred; Heckel, Werner; Biermann, Stefan (Schweizer Maschinenmarkt, 1990)
LFT Import::2019-07-15 (728)

Neue Ideen zum Innenhochdruckumformen. - Geiger, Manfred; Hein, Philipp (Blech, Rohre, Profile, 1996)
LFT Import::2019-07-15 (643)

Neue Möglichkeiten beim Laserstrahlkunststoffschweißen - Polster, Steffen; Wiengarten, M. (LEF 2003, Laser in der Elektronikproduktion & Feinwerktechnik - Tagungsband des 6. Erlanger Seminars LEF (2003), 2003)
LFT Import::2019-08-05 (975)

Neuere Entwicklungen zur Umformung höchstfester Stahlwerkstoffe - Merklein, Marion; Pitz, Matthias; Hoff, Cornelia; Lechler, Jürgen (Multifunktionale Bauteile und Verfahren zur Erhöhung der Wertschöpfung in der Blechbearbeitung, 2005)
LFT Import::2019-07-16 (1178)

Neue Regelstrategien beim freien Biegen. - Heckel, Werner (Blech, Rohre, Profile, 1996)
LFT Import::2019-07-15 (672)

Neue Wege der Innenhochdruckumformung. Innenhochdruckumformen, eine Alternative in der Fertigungstechnik. - Geiger, Manfred; Vollertsen, Frank; Hein, Philipp (EFB Kolloquium Stuttgart, 1996)
LFT Import::2019-08-05 (657)

Neural Networks in Metal Forming. - Geiger, Manfred; Cser, L.; Lenard, J.; Farkas, K.; Backes, Frank; Hwu, Y. (Preprints of the Second International Work- shop on Learning in Intelligent Manufacturing Systems LIMS, 1995)
LFT Import::2019-08-05 (530)

Neural Networks Matching Contours in CAD Models - Wilke, Peter; Greska, Wolfgang; Geiger, Manfred; Berentz, Jörg (1994)

Neuronale Netze zur Konturanalyse in CAD-Modellen - Greska, Wolfgang; Wilke, Peter; Geiger, Manfred; Berentz, Jörg (Zeitschrift für Wirtschaftliche Fertigung und Automatisierung, 1994)

New Applications of Nondestructive Testing in Forming Technology. - Engel, Ulf; Schwind, Michael; Niederkorn, Sorin (Proceedings of the Institution of Mechanical Engineers. Part B. Management and engineering manufacture, 1994)
LFT Import::2019-07-16 (1948)

New Approaches in Laser-Based Micro Adjustment as a Key Technology for ultra Precision Assembly - Schmidt, Michael; Dirscherl, Manfred; Bechtold, P. (Proceedings of the 7th Euspen International Conference, 2007)
Many micro system devices such as computer hard disk drives or micro-optical structures are crucially depending on the precise alignment of specific lenses, sensors or other functional components. The problem of meeting the tight positioning tolerances represents an up-to-date key assignment in ultra precision manufacturing and assembly. Instead of individual, high-precision manufacturing of each component, its accurate adjustment after assembly has turned out much cheaper and easier to perform. The components themselves and most of the process steps during assembly are in this case allowed to possess loose tolerances because the precise adjustment of all critical components is performed later in a separate process step. Unlike most other alternatives, laser driven alignment processes represent a very elegant and convenient way to manipulate mounted components in a micron and submicron range. As miniaturized devices are typically difficult to access and highly sensitive to mechanical forces and impacts, especially applications in micro technology benefit from the general advantage of laser adjustment processes to allow a completely contact free interaction. Moreover, the laser offers unmatched flexibility and controllability as well as ideal adaptability to the process and the application. As all established laser adjustment processes are based on thermally induced stress and therefore limited in both accuracy and applicable actuator materials, new nonthermal adjustment mechanisms using ultrashort laser pulses have been investigated and theoretically and experimentally demonstrated. This contribution will therefore both give latest scientific information on novel laser forming mechanisms and focus on possible applications for the near future in the field of micro manufacturing and assembly.
LFT Import::2019-08-05 (1405)

New approaches to determine the bending contour of the 3-roll-push-bending process - Vatter, Peter; Plettke, Raoul; Merklein, Marion (7th Int. Conf. on Design and Production of Machines and Dies/Molds, 2013)
LFT Import::2019-08-05 (1880)

New Approach on the Allocation of Wear Allowances - a Case Study - Schubert, Dominik; Rohrmoser, Andreas; Hertle, Sebastian; Wartzack, Sandro; Hagenah, Hinnerk; Merklein, Marion; Drummer, Dietmar (22nd International Conference on Engineering Design (ICED19), 2019)

New developments and perspectives of forming technology at the LFT - Geiger, Manfred; Merklein, Marion; Celeghini, Martino; Eckstein, Ralf; Novotny, Stefan (Proceedings of the 10th International Conference on Sheet Metal, SheMet 2003, 14.-16.04., Jordanstown, 2003)
LFT Import::2019-08-05 (957)

New Developments for the Qualification of Technical Surfaces in Forming Processes - Geiger, Manfred; Engel, Ulf; Pfestorf, Markus (CIRP Annals - Manufacturing Technology, 1997)
In modern sheet metal forming, blank topographies are characterized by various quite different and rather sophisticated structures. This is due to the various deterministic or semi-deterministic methods of surface texturing produced by skinpass rolling. The conventional surface parameters determined from profile data are not capable of characterizing such surfaces, in particular with respect to their functional behavior. Thus, there is a strong demand for the development of new parameters which can only be determined via the measurement of area. With special respect to the application of deterministically textured topographies in metal forming, appropriate 3d surface parameters can be derived from the mechanical rheological model recently developed at the Institute of Manufacturing Technology. These are the maximum ratio of closed void area and the closed void volume, both of which result from a special evaluation of the bearing ratio curves. Industrial applications show that these parameters can be related to the functionality of the surface and hence may be regarded as very suitable for the characterization and qualification of complex surface structures.
LFT Import::2019-07-16 (1989)
Keywords: Forming; Rolling; Topography

New Developments in Laser Processing of Silicon Devices - Dirscherl, Manfred; Eßer, Gerd (Proceedings of SPIE Vol. 4977 Photon Processing in Microelements II, 2003)
Silicon is the standard material for the production of integrated circuits and one of the most important substrates for micro systems technology. It can be produced with an extraordinarily high purity, homogeneity and crystal perfection. Today, laser processing of silicon is becoming increasingly more interesting. This can be partly attributed to the evolution of frequency-converted solid state lasers which emit visible or ultraviolet radiation that is readily absorbed by silicon. Another reason for the growing interest in laser processing of silicon devices is that conventional technologies are approaching their limits. Especially laser cutting of thin silicon wafers as an alternative to mechanical sawing represents a very promising option for industrial applications. This paper shows current research results on laser processing of silicon. Besides laser cutting and ablation with frequency-tripled Nd:YAG lasers and Ti:Sapphire femtosecond lasers, laser welding of silicon with millisecond pulses is a focus of the presented work. When welding Si, the brittle behaviour of the material usually leads to thermally induced cracks. These cracks do typically not occur when cutting with short and ultrashort pulsed lasers. A controlled heating of the work piece can prevent cracks during welding with millisecond pulses as well. Together with laser cutting and welding, laser adjustment of silicon components by ultrashort pulse ablation of pre-stressed layer systems, which is also described in this paper, is another promising approach for high precision manufacturing of silicon micro devices.
LFT Import::2019-08-05 (978)
Keywords: Laser adjustment; Laser cutting; Laser welding; Silicon

New Materials and Surface Finishing Methods for Cold Forging Tools - Engel, Ulf; Arbak, Murat; Wagner, Kay; Völkl, Ralf (Conference Proceedings, ICIT&MPT 2007, 6th International Conference on Industrial Tools and Material Processing Technologies, 2007)
LFT Import::2019-08-05 (1428)

New materials and surface finishing methods for cold forging tools - Engel, Ulf; Völkl, Ralf; Arbak, Murat; Wagner, Kay (International Journal of Microstructure and Materials Properties, 2009)
LFT Import::2019-07-29 (2075)

New method for stress determination based on digital image correlation data - Brosius, Alexander; Kuesters, Niklas; Lenzen, Matthias (CIRP Annals - Manufacturing Technology, 2018)
Accurate material characterisation of anisotropic yielding behaviour for modern sheet metal requires the testing under multiaxial stress conditions like in the shear test or plane strain test. While most approaches include time-consuming finite element simulations for evaluation of inhomogeneous stress distributions, this paper shows a new method to determine stress data based directly on digital image correlation data. This accurate and efficient semi-analytical method can be used in direct stress analysis or inverse material parameter identification schemes as well. The methodology will be described and exemplarily results of the plane strain test and the shear test will be discussed.
LFT Import::2019-07-29 (2303)
Keywords: Forming; Sheet metal; Stress data

New process strategies to manufacture tailored blanks out of DP600 by orbital forming - Hildenbrand, Philipp; Schulte, Robert Karl; Merklein, Marion (Applied Mechanics and Materials, 2015)
LFT Import::2019-07-29 (2115)

New Technologies in sheet metal forming for light-weight construction. - Geiger, Manfred; Müller, Burkhard (Proc. of the 4th Int. Conf. on Sheet Metal, Twente : University of Twente, 1996)
LFT Import::2019-08-05 (651)

New Time Dependent Method for Determination of Forming Limit Curves Applied to SZBS800 - Merklein, Marion; Kuppert, Andreas; Mütze, S.; Geffert, A. (Proc. 50th Conference of IDDRG 2010, 2010)
LFT Import::2019-08-05 (298)

New Tribological Aspects of Dry Film Lubricated Aluminium Sheet Metal - Pfestorf, Markus; Meiler, M.; Merklein, Marion; Geiger, Manfred (Proceedings of the 4th International Conference THE coatings in Manufacturing Engineering, 2004)
LFT Import::2019-08-05 (1096)

Nichtthermische Mikrojustiertechnik mittel Ultrakurzpulslaser - Dirscherl, Manfred (Laser in der Elektronikproduktion & Feinwerktechnik; Tagungsband des 7. Erlanger Seminars LEF 2004, 2004)
LFT Import::2019-08-05 (1041)

Nichtthermische Mikrojustiertechnik mit Ultrakurzpulslasern - Bechtold, P.; Dirscherl, Manfred (Laser in der Elektronikproduktion und Feinwerktechnik - Tagungsband des Erlanger Seminars LEF 2007, 2007)
LFT Import::2019-08-05 (1391)

Non-destructive testing in versatile joining processes - Lechner, Michael; Borgert, Thomas; Busch, Matthias; Harms, Arnold; Holtkamp, Pia; Kappe, Fabian; Römisch, David; Wituschek, Simon (Sheet Metal 2025, 2025)
Abstract. Mechanical joints are traditionally analyzed through destructive micrograph analysis, which may compromise internal geometry and morphology, as evidenced by radial cracks in semi-tubular self-pierce riveting. In contrast, industrial X-ray computed tomography (XCT) offers a non-destructive method for component diagnosis, providing volumetric insights without damaging the sample and enabling dimensional measurement. The DFG-funded Collaborative Research Center TRR 285 is exploring XCT’s application in assessing mechanical joinability across various joining processes and materials, particularly in multi-material systems like steel-aluminum joints. XCT faces challenges in accurately capturing multi-material compositions, leading to artifacts that complicate interface detection. This research aims to validate XCT for joint investigations, yielding quantitative characteristics that surpass those from traditional micrograph analysi
Keywords: Computed Tomography; Metrology; Mechanical Joining

Nonlinear and Stochastic Analysis and Modelling of Laser Beam Melt Ablation as an Approach to Online Process Diagnostics and Control Strategy - Cser, Adrienn Orsolya; Otto, Andreas; Geiger, Manfred (Proceedings of the 4th LANE 2004, 2004)
LFT Import::2019-08-05 (1078)

Nonlinear Dynamics Durin Laser Beam Welding. - Otto, Andreas; Geisel, Mark; Geiger, Manfred (Proc. of the 15th Int. Congress on Application of Laser and Electro-Optics, ICALEO 96, 1996)
LFT Import::2019-08-05 (666)

Novel concept of experimental setup for characterisation of plastic yielding of sheet metal at elevated temperatures - Geiger, Manfred; van der Heyd, Gerhard; Merklein, Marion; Hußnätter, Wolfgang (Advanced Materials Research, 2005)
In times of highest significance of process modelling and numerical simulation characterisation of material properties is of special importance for tools' and components' dimensioning. But in general material properties depend on many different influencing variables, e.g. temperature, humidity and many others. Especially in fields of sheet metal forming the mechanical behaviour of components highly differs according to real stress condition. In particular yield loci combine the information of beginning of yielding with a biaxial stress condition, but nevertheless for many materials they have not been determined yet. For all others the existing values are available only at room temperature. In this paper a novel concept of the experimental setup is shown, with which plastic yielding of sheet metal can be examined also at elevated temperatures. In usual biaxial tension tests cruciform specimen are drawn in plane. The new machine-concept, which is presented in this paper, is based on a punch-load moving perpendicular to the sheet. By clamping the specimen restoring forces are induced, which cause in dependence of special developed tool and work piece geometries defined stress conditions. Using an optical measurement system for determination of strains with CCDcameras of very high frame rate allows exact identification of starting plastification by offline analysis. Experiments at elevated temperatures are realised by local heating with a diode laser and a special optical system to reach a homogenous distribution of temperatures in the forming zone. On the one hand these investigations are necessary for many materials to achieve further information on characteristic properties in warm forming, because their data are only known at room temperature. On the other hand some materials, e.g. magnesium wrought alloys, are mostly formed at elevated temperatures (here in the range of 200°C to 250°C), because of its significant higher formability. Thus, material behaviour must be characterised at these temperatures.
LFT Import::2019-07-16 (1135)
Keywords: Material characterisation; Sheet metal forming; System technology

Novel process chain for forming micro gears with a module of 0.1 mm – Potentials and approaches for extending process limits - Leicht, Miriam; Merklein, Marion (Journal of Manufacturing Processes, 2025)
Micro gears are considered essential components of micro drive systems, which offer great potential for medical technology, measurement technology and robotics due to their small dimensions and their precise and highly dynamic transmission of movements and forces. However, established manufacturing processes such as hobbing, lithography technology or micro powder injection moulding are too time-consuming and cost-intensive for mass production. Therefore, new technological approaches are required. A multi-stage process chain of micro bulk forming from sheet metal offers great potential for the mass production of high-performance micro gears. In the first stage, a pin is extruded from sheet metal. Afterwards, the pin is geared by lateral extrusion, which is subsequently separated from sheet by shear cutting. The objective of this research work is to gain a fundamental understanding of the potentials and limitations of a multi-stage process chain for the production of micro gears with a module of m = 0.1 mm. The obtained knowledge serves as foundation for the development and analysis of approaches to overcome existing process limitations in terms of material efficiency and tool stress. The experimental results reveal, that a local adjustment of the material properties in the forming zone as well as a tool-sided limitation of the material flow radially outwards are suitable for improving the material efficiency.
CRIS-Team Scopus Importer:2025-04-25
Keywords: Cold forming; Micro forming; Micro gear; Size-effect

Novel setup for the investigation of tribological behavior of sheet metal surfaces - Merklein, Marion; Engel, Ulf; Vierzigmann, Ulrich (International Journal of Material Forming, 2009)
In sheet metal forming processes tribological conditions have a significant influence on the quality of the produced part, the tool life time as well as the process stability. Due to the contact pressures in the workpiece-tool interface, mixed lubrication is predominant. Thus, the appearing real contact area has a major influence on the frictional conditions. During the forming process the real contact area increases, because of the flattening of topography asperities. For the investigation of flattening behaviour and the so connected changes in friction a new modular test rig for strip drawing tests has been developed. To gain additional information about the contact behaviour of texturized sheet metal surfaces during the tests, it is possible to alternate between two different measurement setups to investigate changes in the workpiece-tool interface in-situ. In the first setup, an ultrasonic inspection system is used while the second setup is based on optical techniques. In this paper the two measurement setups and the planned investigations are described. © Springer/ESAFORM 2009.
LFT Import::2019-07-29 (287)
Keywords: Flattening behaviour; In-situ investigation; Real contact area

Novel technique for high-quality microstructuring with excimer lasers - Roth, Stephan; Geiger, Manfred (Proceedings of SPIE, 2000)
Laser micromachining has become increasingly established in many microsystems applications during the past years. These new fields occasion higher demands on the quality of micromachined devices combined with high resolution and working velocity. Due to the disadvantages of conventional excimer laser processing, a novel technique is required to meet these demands. The main problems of conventional excimer laser machining are the redeposition of ablated material on the irradiated work piece and the formation of a strong melting phase especially for metals. These difficulties greatly reduce the applicability of excimer laser material processing for manufacturing microsystems technology components. By applying a thin water film to the substrate surface, the redeposition of ablated material can be completely avoided, which results in a better quality of the microstructures. Usage of a water film, however, has proved to lead to a marked reduction of the ablation rate for the examined materials - ceramics and stainless steel. Therefore, one of the objectives of future research will be to raise the ablation rate in order to render excimer laser processing more interesting economically. Adding alcoholic additives, among others, has improved the wetting of the liquid films on the surface. The effect of the modified chemical composition of the liquid on ablation rate and structure quality for various materials is presented here.
LFT Import::2019-07-15 (799)

Numerical and Experimental evaluation of thermal dependent flc - Hora, P.; Merklein, Marion; Tong, L.; Lechler, Jürgen (Tagungsband IDDRG Conference 2007, Györ, Ungarn, 2007)
LFT Import::2019-08-05 (1458)

Numerical and experimental investigation of a backward extrusion process for forming geared components from coil - Leicht, Miriam; Henneberg, Johannes; Merklein, Marion (Materials Research Proceeding, 2023)
Stricter political regulations, increasing ecological awareness of society as well as the pursuit for higher performance of components motivate lightweight construction. Functional integration is one way to realize lightweight design, resulting in increased demands on component geometry. Sheet-bulk metal forming (SBMF) offers the potential to enable an economic and ecological production of functional components through short process chains. SBMF from coil also provides additional advantages regarding high output quantity and short cycle times. However, the industrially application of SBMF from coil is limited due to high tool load and coil-specific challenges like an anisotropic material flow, which negatively affects the part accuracy. In this study, a backward extrusion process from coil for forming functional components with gearing is investigated. Therefore, a numerical process model was built and validated based on experimental results. In order to generate a profound process understanding, a combined numerical-experimental approach was chosen for a fundamental process analysis. The influence of the semi-finished product geometry was investigated by forming rotationally symmetric, pre-cut blanks and coil material. The application of the different sheet geometries was compared based on component- and process-side target quantities. The results indicate an anisotropic material flow as a coil-specific challenge, which leads to a direction-dependent component formin

Numerical and experimental investigation of dry deep drawing of aluminum alloys with conventional and coated tool surfaces - Tenner, Jennifer; Andreas, Kolja; Radius, Adrian; Merklein, Marion (International Conference on the Technology of Plasticity (ICTP), 2017)
LFT Import::2019-08-05 (2245)
Keywords: deep drawing; DLC coatings; dry forming; tribology

Numerical and experimental investigation of extrusion processes from coil - Leicht, Miriam; Merklein, Marion (Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2024)
The use of coil material as semi-finished product in sheet-bulk metal forming (SBMF), offers the possibility to use high-speed presses and thus to achieve high output quantities. However, compared to industrially established forming of pre-cut blanks, the reduced geometric accuracy of the parts due to the asymmetrical material flow represents a challenge. Against this background, the aim of this study is to gain an in-depth knowledge on the influence of the process setup on the material flow direction and on the forming of geared functional parts. A combined numerical-experimental approach of each a lateral and a backward extrusion process of a DC04 sheet metal (t0 = 2 mm) is applied for a fundamental process analysis. For this purpose, process-dependent causes for the asymmetric part forming are analyzed by means of material flow simulations. Subsequently, the numerical results are verified experimentally in terms of the part geometry, the process force and grain structural changes. Based on the numerical and experimental results, cause-effect relations between material flow, part accuracy and tool load are derived. In addition, the transferability of the causes of the asymmetric material flow to processes with different primary material flow directions and part geometries is verified. The findings facilitate the future counteraction of asymmetrical material flow in SBMF from coil, which in turn leads to enhanced component quality.
CRIS-Team Scopus Importer:2024-09-27
Keywords: cold forming; extrusion; Sheet-bulk metal forming

Numerical and experimental investigation on full backward extrusion process in forming of pins from DC04 coil - Luo, Keyu; Vogel, Marion; Vogel-Heuser, Birgit; Merklein, Marion (Materials Research Proceedings, 2025)

Numerical and experimental investigation on the material flow in an orbital forming process to join functional components from dissimilar materials - Harms, Arnold; Hetzel, Andreas; Lechner, Michael; Merklein, Marion (Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2025)
The manufacturing industry is currently facing major challenges. Environmental protection requirements, component complexity and material costs are continually growing. Lightweight design offers a solution, particularly in hybrid components, reducing weight while maintaining strength. Joining by forming processes based on plastic deformation offer high material efficiency and a reduced number of required parts. However, industrially established processes oppose a lack in flexibility for varying material thickness and strength class. Current research focuses on innovative and versatile mechanical joining processes. In this context, the process of orbital forming was investigated to be used as mechanical joining operation for dissimilar materials. The rotational movement of the tool enables a radial material flow, ensuring permanent form and force closure. To establish a reliable joint, a fundamental understanding of the process in terms of the material behavior is necessary. Therefore, the main focus of this investigation is introducing a novel numerical and experimental approach to identify the material flow during forming. A numerical model is utilized to simulate an orbital forming process and analyze the stress conditions as well as the resulting material flow. The joining partners include the dual-phase steel DP600 and the aluminum alloy EN AW-5754 with a thickness of 3.0 mm. The numerical simulation indicates that with increasing forming force, the material flow increases due to elevated compressive stresses. This assumption is confirmed by experimental investigations using various forces. In addition, the geometrical and mechanical properties of the joint were measured in further investigations, in order to validate the numerical process model.
CRIS-Team Scopus Importer:2025-06-13
Keywords: Forming; hybrid semi-finished components; lightweight design; mechanical joining; numerical modeling; orbital forming; sheet-bulk metal forming; simufact forming; versatile joining process

Numerical and experimental investigations for distortion-reduced laser heat treatment of aluminum - Rigas, Nikolaos; Merklein, Marion (Production Engineering, 2021)
In the field of mobility, increased safety and emission requirements lead to steadily rising demands on materials used and their performance. Over the last decades, 5000 and 6000 series aluminum alloys have become more and more attractive as lightweight material due to their beneficial weight to strength ratio. The 7000 series offers extended lightweight potential due to its high strength. Until now, this class of alloys has not been widely used in mass production due to its limited corrosion resistance and poor forming behavior. By using so-called Tailor Heat Treated Blanks, it is possible to set increased forming limits of previously locally heat treated components. The reason for the enhanced formability is the local softening, with the resulting improved material flow and the reduced critical forming stresses of the sheet metal before the forming operation. Despite these advantages, the use of previously heat treated materials has been very limited so far. For example, the distortion that occurs during local heat treatment reduces geometrical accuracy and thus automated handling. Therefore, the focus of this thesis is the investigation of tailored heat treatment strategies, permitting a distortion-reduced local short-term heat treatment. For this purpose, the distortion behavior is represented and quantified both numerically and experimentally. The generated knowledge is then transferred to a large volume component and characterized.
CRIS-Team Scopus Importer:2021-03-26
Keywords: AA7075; Distortion; Mechanical properties; Simulation; Tailor Heat Treated Blanks

Numerical and experimental investigations on the mechanical properties of milled specimens from an AA7020 tube - Reblitz, Jonas; Reuther, Franz; Trân, Ricardo; Kräusel, Verena; Merklein, Marion (Achievements and Trends in Material Forming, 2022)
The reduction of weight is crucial in the automotive sector to reach a lower energy consumption and an increased range, especially for electrically powered vehicles. In this regard, body-in-white parts offer a high potential for the application of lightweight construction. The required weight savings can be achieved by implementing parts with a high strength-to-weight ratio. A promising approach is the combination of lightweight materials and lightweight design, which can be realized by tubular components made of high strength aluminum. Due to their structural stiffness and high crashworthiness, those structures are often used as safety-relevant car body components. However, the material characterization of tube profiles is a major challenge, which in turn impedes an accurate numerical simulation and precise process design. In contrast to flat semi-finished parts, various effects of the production process and the geometry, regarding the stress state under load, must be taken into account. For this purpose, adapted testing methods considering the geometrical and mechanical properties of the tubular parts have to be investigated, in order to generate an accurate material model and process design. Within this research work, tubular components made out of AA7020 in W-temper condition were used to analyze the mechanical properties. In this regard, several tensile specimens are milled from a tube, so they also have a curvature profile. The experimental tensile tests have been performed at different strain rates by using a universal testing machine from type Gleeble 3500. To ensure a proper measurement of the mechanical properties, the clamping jaws of the testing machine are adjusted to the curved samples. The investigated material parameters are subsequently transferred to an FE model with curved specimen to enable an accurate prediction of the forming behavior. In addition, an FE model of a flat tensile specimen was also created for comparison, in order to gain a profound knowledge regarding the influence of the geometric and mechanical properties of tubular components. <
Keywords: Material characterization; W-temper condition; tensile test; tubes

Numerical Investigation for Superplastic Forming Tool Development Within the Combined Process Chain of Forming and Additive Manufacturing - Schaub, Adam; Degner, Julia; Ahuja, B.; Schmidt, M.; Merklein, Marion (Int. Conf. Competitive Manufacturing, 2016)
Key motivation behind the combination of superplastic forming and additive manufacturing is to merge the advantages of two different manufacturing methods. On the one hand the efficiency to form large scaled parts by superplastic forming and on the other hand additive manufacturing of highly customised products. While the combination of additive manufacturing with bulk structures is state of the art, combining sheet metal parts with additive functional elements is hardly investigated. Few research works have been published regarding additively manufactured functional elements on deep drawn sheet parts. As forming is limited for Ti-6Al-4V at room temperature and even at moderate temperatures, this paper presents a new and innovative manufacturing process chain, where superplastic forming and additive manufacturing is combined to merge the advantages of both. Within this work the possibilities of additive manufacturing on sheet metal is presented in addition to the numerical simulation of superplastic forming of Ti-6Al-4V to produce a semi-finished sheet part for subsequent additive manufacturing process. As a result of this study a LS-DYNA based numerical model is presented for tool development as well as process simulation for superplastic forming of semi-finished parts which can be utilized for consecutive additive manufacturing operation.<br
LFT Import::2019-08-05 (2154)
Keywords: Superplastic Forming; Additive Manufacturing; Ti-6Al-4V

Numerical investigation of dry and lubricated sheet metal forming processes - Merklein, Marion; Affronti, Emanuela; Steiner, Jennifer (Key Engineering Materials, 2015)
LFT Import::2019-08-05 (2091)
Keywords: Dry forming; Metal forming; Sheet metal

Numerical investigation of small curvature bendability of high strength low alloyed steel in air and die bending processes - Tsoupis, Ioannis; Hildering, Sven; Merklein, Marion (Proc. IDDRG 2013, 2013)
LFT Import::2019-08-05 (1884)

Numerical investigation of temperature and phase development of (deformation-) dilatometer specimens - Lutz, Stefan; Weninger, Johannes; Helldoerfer, Bastian; Merklein, Marion (Material Forming - ESAFORM 2014, 2014)
The Gleeble 3500 thermo-mechanical testing machine with ISO-Q dilatometer set-up allows the creation of time temperature transformation diagrams at high cooling rates, after deformation and under constant load with a simple experimental set-up. An isothermal plane with temperature gradients perpendicular to this plane arises in the sample which is used for dilatometrical evaluation. The homogeneity and size of this isothermal region has a decisive influence on the measurement results, but cannot be measured with sufficient accuracy. To gain an accurate understanding of the processes in the sample, a coupled thermo-electrical, thermo-metallurgical, thermo-mechanical finite element model of the experiments is set up. To map the temperature control circuit of the machine, a PID controller is implemented, which controls the voltage of the conductive sample heating between the simulation steps. By comparing the temperature and hardness distribution with the experiments, it is shown that in this way the temperature distribution and phase transformation can be mapped. By the findings, the experimental setup was adjusted. This led to an improvement of the measurement results. © 2014 Trans Tech Publications, Switzerland.
LFT Import::2019-08-05 (2016)
Keywords: Closed loop control; Heat treatment; Numerical simulation; Quenching dilatometry

Numerical Investigation of the Influence of a Movable Die Base on Joint Formation in Semi-tubular Self-piercing Riveting - Kappe, Fabian; Wituschek, Simon; de Pascalis, Vincenzo; Bobbert, Mathias; Lechner, Michael; Meschut, Gerson (Materials Design and Applications IV, 2023)
Due to economic and ecological requirements and the associated trend towards lightweight construction, mechanical joining technologies like self-piercing riveting are gaining in importance. In addition, the increase in lightweight multi-material joints has led to the development of many different mechanical joining technologies which can only be applied to join a small number of material combinations. This leads to low process efficiency, and in the case of self-piercing riveting, to a large number of required tool changes. Another approach focuses on reacting to changing boundary conditions as well as the creation of customised joints by using adaptive tools, versatile auxiliary joining parts or modified process kinematics. Therefore, this study investigates the influence of increased die-sided kinematics on joint formation in self-piercing riveting process. The aim is to achieve an improvement of the joint properties by superimposing the punch feed. Furthermore, it is intended to reduce required tool changes due to the improved joint design. The investigations were carried out by means of a 2D-axisymmetric numerical simulation model using the LS-Dyna simulation software. After the validation of the process model, the die was extended to include driven die elements. Using the model, different kinematics as well as their effects on the joint formation and the internal stress concentration could be analysed. In principle, the increased actuator technology enabled an increase of the interlock formation for both pure aluminium and multi-material joints consisting of steel and aluminium. However, the resulting process forces were higher during the process phases of punching and spreading.
Created from Fastlane, Scopus look-up
Keywords: Die-side kinematic; FEM; Self-piercing riveting; Versatility

Numerical Investigation of the Tool Load in Joining by Forming of Dissimilar Materials Using Shear-Clinching Technology - Wiesenmayer, Sebastian; Müller, Martin; Dornberger, Peter; Han, Daxin; Hörhold, Réjane; Meschut, Gerson; Merklein, Marion (Key Engineering Materials, 2018)
LFT Import::2019-07-29 (2301)
Keywords: Finite element method; Joining; Shear-clinching; Tool

Numerical investigation on the deep drawing of sheet metals with an additively applied coating - März, Raphaela; Hafenecker, Jan; Bartels, Dominic; Schmidt, Michael; Merklein, Marion (Material Forming, 2023)
A promising approach to meet ecological and economical challenges in production industry is the combination of additive manufacturing and forming, which enables the production of hybrid parts. The fusion of the two technologies has the potential to use the benefits of both process classes. One example for the combination of additive manufacturing and forming is a process chain consisting of laser-based directed energy deposition (DED-LB/M) to apply a wear resistant coating on a sheet metal and a subsequent deep drawing process to achieve the final geometry of the component. However, the presence of the local reinforcement influences the subsequent sheet metal forming process. In order to gain more knowledge about the process chain a numerical approach is performed. In this work, the influence of a coating using Bainidur® AM applied by DED-LB/M on the formability of the case hardening steel 16MnCr5 in a deep drawing process is evaluated. For this purpose, a numerical model is built and validated by comparison with experimental results. The finite-element-model serves as the basis for the investigation on the influence of the location of the additively applied coating on the deep drawing process and also enables a deeper understanding of the proces
Keywords: Additive Manufacturing; Forming; Hybrid Parts

Numerical investigations on the influence of process parameters on the forming of gears in forward extrusion - Merklein, Marion; Kiener, Christoph; Zimmermann, Andrea (Applied Mechanics and Materials, 2015)
LFT Import::2019-07-29 (2128)

Numerical modelling approach for the temperature dependent forming behaviour of Ti-6Al-4V - Papke, Thomas; Graser, Matthias; Merklein, Marion (Proceedings of the 5th International Conference on New Forming Technology, MATEC Web of Conferences, 2018)
Titanium alloys offer several beneficial characteristics, such as high specific strength, metallurgical stability at elevated temperature, biocompatibility and corrosion resistance. With regard to these superior properties, Ti-6Al-4V is a commonly used titanium alloy for aerospace components and medical products. The production of parts made of Ti-6Al-4V can be done in various ways. One approach is forming at elevated temperature, which requires a focused design of parts, processes and numerical modelling of the forming process. Essential input parameters for the numerical models are temperature dependent material parameters. Since, the yield stress and Young's modulus of the material decrease significantly at elevated temperature, the forming limits are enhanced. For the characterization of the forming behaviour, uniaxial tensile tests at temperatures from 250 °C to 400 °C have been conducted. The samples are heated by conduction in a thermal-mechanical simulator for the tensile test. However, the resulting inhomogeneous temperature distribution along the longitudinal axis of the specimen is a challenge in order to measure proper material properties. Inhomogeneous temperature distribution leads to varying mechanical properties and temperature dependent forming behaviour. To overcome this issue, simple numerical models based on experimental data are necessary, which allow the estimation of the influence of the inhomogeneous temperature distribution. In this paper, therefore, the temperature distribution and the subsequent tensile test are investigated using electrical-thermal and mechanical numerical simulations of the tensile test at elevated temperature. With the combined approach of experimental tests and numerical simulations, the forming behaviour of Ti-6Al-4V can be modelled.
LFT Import::2019-08-05 (2305)
Keywords: Modelling; Thermal effects; Titanium

Numerical modelling of the process chain for aluminium Tailored Heat-Treated Profiles - Fröck, Hannes; Graser, Matthias; Reich, Michael; Lechner, Michael; Merklein, Marion; Kessler, Olaf (Advanced Modeling and Simulation in Engineering Sciences, 2023)
Lightweight construction in modern car design leads to an increased usage of various aluminium semi-finished products. Besides sheet material, aluminium extrusion profiles are frequently used due to their high stiffness and variety of possible cross-sections. However, similar to sheet material, aluminium profiles exhibit limited formability in comparison to mild steel materials. One possibility to increase the forming limits of precipitation hardened aluminium alloys is the so-called Tailored Heat Treatment technology. By a local short-term heat treatment, the material is softened and the material flow can be controlled to reduce stresses in critical forming zones. The purposeful definition of the heat treatment zones is mandatory to improve the forming results. Therefore, numerical methods are necessary. In this investigation, a numerical process chain is presented. It combines the thermo-mechanical simulation of a local laser heat treatment with a subsequent bending process of the heat-treated profile using the alloy EN AW-6082. The temperature distribution, mechanical properties, and finally, the bending result of the numerical model are validated by experimental tests.
CRIS-Team Scopus Importer:2023-06-30
Keywords: Aluminium alloy; Anisotropy; Bending simulation; EN AW-6082; LS-Dyna; Material model; Process chain simulation; Tailored Heat-Treated Profiles

Numerical Model of Tube Freeform Bending by Three-Roll-Push-Bending - Hagenah, Hinnerk; Vipavc, Daniel; Plettke, Raoul; Merklein, Marion (2nd International Conference on Engineering Optimization, 2010)
LFT Import::2019-08-05 (508)

Numerical optimisation of a shear specimen geometry according to ASTM - Merklein, Marion; Hofmann, Maren; Biasutti, Manfredi; Lechner, Michael (Key Engineering Materials, 2013)
Complex material models used for the numerical representation of forming processes need in addition to tension and compression tests also shear tests to completely analyse the behaviour of the material under different loading conditions. There are two concepts of shear test - one uses symmetrical specimens with two shear zones (according to Miyauchi) the other one specimens with a single shear zone. In both cases, a homogeneous distribution of the strain in the shear zone is essential for the validity of the shear test. Therefore, the length and width of the shear zone in a single shear specimen made from high strength steel according to the ASTM standard geometry were varied. Analysing the resulting strain distribution numerically an optimised sample geometry with a more uniform strain distribution than the ASTM standard was achieved. The numerical results were also validated with experimental shear tests. © (2013) Trans Tech Publications.
LFT Import::2019-07-29 (1857)
Keywords: ASTM specimen geometry; Numerical optimisation; Simple shear test

Numerical Prediction of Failure within Small Curvature Bending of Advanced High Strength Steels - Tsoupis, Ioannis; Merklein, Marion (Key Engineering Materials, 2015)
Within this paper a numerical study of the Continuum Damage Mechanics based damage model Lemaitre in commercial software LS-DYNA is performed in order to correctly predict failure in terms of crack occurrence within small curvature bending of AHSS steels. A strain based calibration method is used for the effective adaption of the Lemaitre model to the bending operation, which is based on the comparison and adaption of the numerically calculated and the experimentally measured deformation field on the outer surface of the bent specimen. Within this method the material dependent damage parameter S is systematically varied in the simulation in order to represent maximum major strain. The new method is proved by numerical simulation of experiments provoking crack initiation using smaller bending radii. It can be shown that failure in terms of crack initiation can be correctly predicted by the model with the damage parameters, which were determined by the method of strain based calibration and an additional optimisation of the parameter Dc. Thus, within this study a user friendly and effective way for the application of Lemaitre damage model to small curvature bending processes of AHSS steels is developed.
LFT Import::2019-07-29 (2076)
Keywords: Bending; Damage; Simulation

Numerical process design of hot stamping processes based on verified thermo mechanical characteristics - Karbasian, H.; Brosius, A.; Tekkaya, A. E.; Lechler, Jürgen; Merklein, Marion (Technology Conference MS&T’08, 2008)
This paper presents a Finite Element Simulation of hot stamping processes by means of experimentally calculated material and process data for the process design. The quality and the significance of the simulation results are strongly dependent on the accuracy of the thermal and mechanical parameters used in FE models. Therefore, the process and material parameters used in the FE model in this investigation were optimized with a statistical method and by means of an experimental analysis. The identification of interaction between the thermal and mechanical parameters was based on design of experiments. This statistical method ensured an efficient analysis of the process parameters consisting of heat transfer coefficients as well as thermal and mechanical characteristics of material. Insights from design of experiments need to be applied in order to enable an efficient FE modeling of hot stamping for process optimization and process design. © 2008 MS&T'O8®.
LFT Import::2019-08-05 (1549)
Keywords: FEM; Hot stamping; Material properties 22MnB5; Process design

Numerical simulation of friction in metal forming using a halfspace model - Hauer, Franz; Vierzigmann, Ulrich; Willner, Kai; Engel, Ulf (AIP Conf. Proc. 1536, 2011)
Sheet and bulk metal forming are widely used manufacturing methods. The industrial trend towards function integration leads to a demand for workpieces having features of both methods. The new forming technology sheet-bulk metal forming is a promising approach to manufacture workpieces with functional elements. Tribological aspects generally play an important role in metal forming processes. Especially for the formability of functional elements friction is very important. The coexistence of low and high contact pressures is characteristic of sheet-bulk metal forming and presents a challenge for the friction modelling. The surfaces of tool and workpiece are always rough so that initial contact only occurs at the asperities of surface roughness. Consequently for small and moderate loads the real contact area is smaller than the apparent contact area. Surface traction can only occur in the real contact area so that it is necessary to determine the real contact area in order to study the tribological behaviour of contact pairs. In order to get an accurate determination of the real contact area it is necessary to calculate the surface deformation in a three-dimensional model and to validate the simulation model by measurements. The halfspace approach has the significant advantage that only the surface has to be discretised while in a Finite Element Analysis the whole bulk has to be discretised. Consequently the numerical effort and thus the calculation time in the halfspace model are much lower than in FE-modelling. The numerical solution scheme based on the halfspace theory is presented in this paper. Results of the calculation of the real contact area of rough surfaces are compared to experimental data from ultrasonic inspection. Friction coefficients calculated with the halfspace model are compared to results of strip drawing tests. © 2011 American Institute of Physics.
UnivIS-Import:2015-04-16:Pub.2011.tech.FT.FT-TM.numeri_9
Keywords: friction; halfspace model; metal forming; real contact area; Simulation; strip drawing; ultrasonic inspection

Numerical simulation of hydraulic bulging using uniaxial and biaxial flow curves and different yield criteria - Prakash, Ved; Kumar, D. Ravi; Merklein, Marion; Hagenah, Hinnerk (IOP Conference Series: Materials Science and Engineering, 2019)
In sheet metal forming industry, finite element analysis has become a necessary step before actual production of the parts. It helps in the improvement of part quality as well reduces the effort applied in experimental trials. However, the success of finite element simulation mainly depends on the constitutive model used for defining the plastic deformation behaviour of the sheet material. Material characterization in biaxial stress state helps in selecting advanced constitutive models in numerical simulations. In this work, aluminium alloy AA5083 sheet material is characterized in uniaxial and biaxial tension conditions. Hydraulic bulge tests are performed to obtain the flow curves and material properties which are then used to find the coefficients in different yield criteria. These coefficients and the flow curves, fitted using different work hardening laws, are used in finite element simulation of the hydraulic bulge test and the results are validated by experiments.
CRIS-Team Scopus Importer:2020-02-21

Numerical Simulation of Hydroforming at Elevated Temperatures with Granular Material Used as Medium Compared to the Real Part Geometry - Grüner, Martin; Merklein, Marion (International Journal of Material Forming, 2010)
LFT Import::2019-07-29 (299)

Numerical simulation of sheet metal forming of an Al-Mg alloy incorporating plane strain properties in the yield criterion - Prakash, Ved; Digavalli, Ravi Kumar; Lenzen, Matthias; Hagenah, Hinnerk; Merklein, Marion (Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2024)
In this work, numerical simulation of AA5083-O aluminum alloy sheets is carried out using Yld2000-2d yield criterion to predict thinning and variation of load with displacement in sheet metal forming. It has been found that the accuracy of predictions in numerical simulation depends on the coefficients and the stress exponent used in the yield criterion. Hydraulic bulge tests with circular and elliptical die cavities are performed to characterize the material in equi-biaxial and plane strain conditions. An improved stress exponent is determined by incorporating the material properties obtained in plane strain in the existing criterion. The improved stress exponent is validated by using it in the numerical simulations of cylindrical cup deep drawing and stretch forming at room temperature. The same exponent is also used in the numerical simulations carried out for the case of experiments conducted at 250 degrees C. The predicted thinning and load-displacement variations from the numerical simulations are validated with the experimental measurements. A considerable improvement in the results predicted using the improved stress exponent is observed at both the temperatures.
CRIS-Team WoS Importer:2022-11-25

Numerical simulation of the staking process of clinching fasteners - Weiss, Miriam; Merklein, Marion; Plettke, Raoul (Proceedings SCT2011, 2011)
LFT Import::2019-08-05 (1648)

Numerical simulation to improve robustness in sheet metal forming process chains - Hagenah, Hinnerk; Geiger, Manfred; Merklein, Marion (AIP Conference Proceedings, 2013)
The paper will present developments towards the improvement of the robustness of sheet metal forming process chains. The possibilities and challenges will be demonstrated using two examples. Firstly, the effect of heat treatment to precipitation hardened aluminum sheet metals in order to enlarge the process window for deep drawing operations will be discussed. Numerical simulation can be used to predict the effects of the heat treatment. Using more sophisticated approaches the heat treatment layout and its effects on the forming process can be computed and predicted. Thus the process window can be enlarged and in consequence the process chain will receive an increased robustness. Secondly the integrated tube and sheet hydroforming process that also includes joining operation will be used as an example of the positive impact numerical simulation can have on complex process chains. This highly integrated process chains needs carefully designed tools that ensure robust production. Furthermore, several effects occurring during the forming operations are difficult to understand since the process cannot be stopped at arbitrary moments or easily investigated in situ. The needed understanding and therefor the mandatory input for successful and robust process design has to be derived from advanced numerical models and the according simulation runs. © 2013 AIP Publishing LLC.
LFT Import::2019-07-29 (1899)
Keywords: Robust process chains; sheet hydroforming; tailored heat treatment

Numerical springback prediction for high-strength aluminum alloys based on the sheet metal upsetting test - Hetz, Peter; Merklein, Marion (Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2024)
Springback prediction continues to play a special role in the process design of sheet metal forming processes. During the forming process, elastic energy is stored in the sheet metal, which is released after the tool is opened. The dimensional accuracy and the function of the component in particular can be negatively affected by this. For this reason, the springback is predicted by means of numerical modeling in order to improve the process design. The simulation accuracy depends primarily on the used material model to map the stress-dependent material behavior and the quality of the experimental input data. High-strength aluminum alloys, which have a distinctive springback behavior, have a slightly pronounced tensile-compressive asymmetry. Since tensile and compressive stresses often occur in sheet metal forming processes, the consideration of this effect can lead to an improvement in springback prediction. Besides modeling the yield locus curve for describing the yield strength in the plane stress area, the yield curve data is also relevant for determining the strain hardening behavior. The work hardening is usually characterized by the tensile test or the hydraulic bulge test, which is used to describe the material behavior in the tensile stress state. A promising experimental method for the analysis of the material in the uniaxial compressive stress state is the sheet metal upsetting test. In addition to a local characterization of sheet metal materials, this test also enables the investigation of the material behavior at significantly higher plastic strains than in the tensile test. Thus, in this contribution it is examined to what extent the sheet metal upsetting test is suitable for improving the springback prediction quality of material models in sheet metal forming processes.
CRIS-Team Scopus Importer:2024-11-01
Keywords: high-strength aluminum alloys; material characterization; Springback; upsetting test

Numerical study on local short-term heat treatments for joining by forming of high-strength 7xxx aluminum - Wiesenmayer, Sebastian; März, Raphaela; Merklein, Marion (Production Engineering, 2023)
7xxx aluminum alloys have very high specific strengths, making them interesting for manufacturing car bodies. However, the limited formability of the precipitation hardenable alloys in the artificially aged T6 temper is challenging for forming and joining processes. The pre-conditioning of aluminum sheets by a short-term retrogression is a promising approach to enhance the process limits of joining by forming technologies. In addition, localizing the heat treatment enables the control of the material flow. However, for a targeted material flow, a deeper understanding of the relation between the heat treatment layout and its influence on joining processes is needed, which can be achieved with the aid of numerical analyses. Therefore, within the scope of this work, an approach for the numerical simulation of locally limited heat treatment layouts for the control of the material flow of high-strength aluminum sheets in joining by forming process is shown. The investigations are conducted for the simulation software LS-DYNA and the innovative shear-clinching process. Process models for the local retrogression heat treatment of punch-sided AA7075 T6 and the subsequent shear-clinching as well as an approach to couple the individual models are presented. By performing a localized retrogression from the T6 temper, the radial material displacement of the upper sheet in the shear-clinching process can be reduced in comparison to joining AA7075 in the W temper. The control of the material flow in the joining process thereby causes the improvement of geometric features, which are critical for the joint strength.
CRIS-Team Scopus Importer:2023-05-26
Keywords: Heat treatment; High-strength aluminum; Joining; Numerical simulation; Shear-clinching

Numerische Abbildung des Tailored Tempering Prozess: Wärmeübergang, FE-Simulation und Ableitung des resultierenden Gefüges - Svec, Thomas; Merklein, Marion (14. Workshop - Simulation in der Umformtechnik, 2011)
LFT Import::2019-08-05 (1651)

Numerische Auslegung eines kombinierten Umform- und Abschreckprozesses zur Herstellung hochfester Aluminiumbauteile - Degner, Julia; Merten, M.; Merklein, Marion (Tagungsband zum 13. Erlanger Workshop Warmblechumformung 2018, 2018)
LFT Import::2019-08-05 (2350)

Numerische Simulation der Verschleißvorgänge in der Umformtechnik - Sobis, Tomasz; Engel, Ulf; Geiger, Manfred (Berichtsband der DGM zum Symposium -Reibung und Verschleiß- Bad Neuheim, 29.-30.Okt.1992 (1993), Oberursel : DGM-Informationsgesellschaft, 1992)
LFT Import::2019-08-05 (488)

Numerische Untersuchung des Werkstoffflusses beim Fügen artungleicher Werkstoffe mittels Schneidclinchen - Müller, Martin; Hörhold, R.; Meschut, G.; Merklein, Marion (Tagungsband SFU 2016, 2016)
LFT Import::2019-08-05 (2191)

Numerische Untersuchungen der Temperatur- und Phasenentwicklung in (Umform-) Dilatometerproben - Lutz, Stefan; Weninger, J.; Helldörfer, B.; Merklein, Marion (Tagungsband "Simulationsforum Schweißen und Wärmebehandlung 2013", 2014)
LFT Import::2019-08-05 (1978)

Oberflächenanalyse von Tailored Blanks hergestellt durch ein Taumelverfahren - Vogel, Manfred; Merklein, Marion (XXXVII. Verformungskundliches Kolloquium, 2018)
LFT Import::2019-08-05 (2292)

Oberflächenausbildung keramischer Bauteile nach einer Endbearbeitung mit Excimerlaserstrahlung. - Geiger, Manfred; Becker, Wolfgang (Tagungsband der Werkstoffwoche 96, Symposium 5, Werkstoffe für die Fertigungstechnik, 1996)
LFT Import::2019-08-05 (635)

Oberflächenausbildung und tribologische Eigenschaften excimerlaserstrahlbearbeiteter Hochleistungskeramiken - Becker, Wolfgang (Friedrich-Alexander-Universität Erlangen-Nürnberg, 1999)
Excimer laser processing offers new possibilities for the surface finishing of ceramics which exceed and/or complete the variety of conventional finishing methods. In order to optimize the surface topography of ceramics for lubricated sliding applications, two different ways of surface treatment by excimer laser radiation are examined: One is the homogeneous modification of the surface topography, i.e. reducing or increasing the roughness or waviness of the ceramics depending on the laser processing parameters. The other possibility is the microstructuring of the surface by a mask projection technique. The surface structures act as lubricant pockets and generate hydrodynamic pressures in the lubricant at high sliding velocities and thus support a full lubricant-film separation of the contact bodies of the bearing. The experimental results indicate that the load-carrying capacity of ceramic bearings is improved both by a homogeneous modification of the surface topography and by the microstructuring of the surface. A significant increase of the lubricant film thickness can be achieved for both examined alternatives. The regime of elastohydrodynamic lubrication could possibly be extended to lower sliding velocities; this could minimize wear-intensive boundary lubrication at frequent starting and running-out procedure

Oberflächenfeinbearbeitung keramischer Werkstoffe mit XeCl-Excimerlaserstrahlung - Lutz, Norbert (Friedrich-Alexander-Universität Erlangen-Nürnberg, 1994)
The aims of the work were fundamentals of surface modification and micro machining of ceramics with XeCl excimer laser radiation and the deduction of hints for industrial application. The surface modification of ceramics is a very promising field of application for excimer lasers. Depending on the energy density and the pulse number the surface can be roughened or smoothed using low pulse numbers. Thin layers of the material are removed above the ablation threshold. A projection scheme produces a demagnified image of the mask at the surface. Lateral dimensions of less than ten microns are obtained with this technique. The observation that the ablation rates increase with increasing temperature of the workpiece can be of technological interest as the processing times can be reduced. The investigation clearly indicates that excimer lasers have the potential for precise machining of ceramic

Oberflächenmodifizierung und Entwicklung einer Auswertemethodik zur Verschleißcharakterisierung im Presshärteprozess - Neubauer, Franziska (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2021)
Growing environmental awareness and the steady rise in vehicle numbers are key challenges for the automotive industry to develop new car concepts. Hot stamping is an established manufacturing process for ensuring occupant safety while reducing the component weight. Compared with conventional forming processes, the tools are subject to massive wear due to the high thermo-mechanical stresses. In order to ensure consistent component quality and reduce maintenance, a suitable wear protection of the tools is required. In this work, two approaches were investigated to increase the wear resistance of hot stamping tools. For this purpose, a laser alloying process and surface coatings were used. The focus of the investigation was on deriving the influence of different alloying elements and element concentrations on the wear behavior. Another essential part of this work was the development of a suitable evaluation methodology in order to determine the wear volume, which enables an evaluation of the different modified surfaces regarding their wear tendency. In the final step, the surface modification was transferred to simple component geometries to ensure its applicability to the hot stamping proces

Oberflächenmodifizierung von Presshärtewerkzeugen durch einen drahtbasierten Laserstrahllegierungsprozess - Neubauer, Franziska; Hofmann, K.; Tenner, Jennifer; Andreas, Kolja; Merklein, Marion (11. Erlanger Workshop Warmblechumformung, 2016)
LFT Import::2019-08-05 (2203)

Observation of Laser Micro Welding Process by Two-Colour-Pyrometry and Measurement of Backreflection. - Brassel, Jan-Oliver; Macher, M.; Schmidt, Michael (Proc. of Laser Assisted Net Shape Engineering LANE 1997, 1997)
LFT Import::2019-08-05 (694)

Offline-Programmierung für die 3D-Laserstrahlbearbeitung. - Backes, Frank (Blech, Rohre, Profile, 1997)
LFT Import::2019-07-15 (687)

On-Line Diagnostic System for the Quality of High Power CO2 Laser Optics - Geiger, Manfred; Hutfless, Joachim (Proc. of GCL 92, 9th Int. Symp. on Gas Flow and Chemical Lasers, Heraklion, Kreta, 1992)
LFT Import::2019-08-05 (476)

On-line Winkelmessung erlaubt Regelung des freien Biegens. - Heckel, Werner (Blech, Rohre, Profile, 1996)
LFT Import::2019-07-15 (671)

On the Determination of the Friction Behaviour of Tailor Welded Blanks by Means of a Cylindrical Cup Drawing Test - Tolazzi, Massimo; Lamprecht, Klaus (Steel Grips, 2006)
LFT Import::2019-07-16 (1266)

On the evaluation of strength of cold forged components made of high nitrogen steel - Noneder, Johannes; Merklein, Marion; Engel, Ulf (Proceedings of the 3rd International Conference on Steels in Cars and Trucks, 2011)
LFT Import::2019-08-05 (1738)

On The Friction Stir Welding of Titanium Alloys: Experimental Measurements and FEM Model Fine Tuning - Buffa, Gianluca; Fratini, Livan; Gnibl, Tobias; Wieland, Michael; Merklein, Marion (Steel Research International, 2012)
LFT Import::2019-07-29 (1791)
Keywords: FEM model; Friction stir welding; Temperature

On the hot deformation behavior of Ti-6Al-4V made by additive manufacturing - Bambach, Markus; Sizova, Irina; Szyndler, Joanna; Bennett, Jennifer; Hyatt, Greg; Cao, Jian; Papke, Thomas; Merklein, Marion (Journal of Materials Processing Technology, 2021)
Innovative process chains that use additive manufacturing (AM) to produce pre-forms for hot forging have been proposed recently, but almost no scientific knowledge on the hot deformation behavior of AM material exists. The combination of AM and metal forming may allow for producing pre-forms by AM which can be forged to the final shape in a single forming operation, thus saving tooling costs compared to conventional multi-stage forging processes. In this work, Ti-6Al-4 V samples made from powder using Directed Energy Deposition (DED) and Selective Laser Melting (SLM) are investigated under typical hot working conditions. An increasing cooling rate in AM promotes the formation of martensite. When heated to forming temperature, the martensite decomposes and yields intermediate microstructures with improved hot working properties compared to conventional wrought material. Differences in the flow stress and activation energy for hot working are analyzed for conventional and as-built Ti-6Al-4 V. AM material exhibits both lower flow stresses and a faster globularization rate, which is explained by non-equilibrium phase fractions and the spatial arrangement of the β-phase. A model is proposed to predict flow stresses and microstructure evolution in Ti-6Al-4 V specimens with a conventional and AM microstructure, which takes the spatial arrangement into account. The findings can be used to design new process chains that allow for single-stage net-shape forging of Ti-6Al-4 V parts at reduced forming forces and with improved mechanical properties.
CRIS-Team Scopus Importer:2020-07-31
Keywords: Additive manufacturing; Hot deformation; Titanium

On the influence of TiB2, TiC, and TiN hard particles on the microstructure of localized laser dispersed AISI D2 tool steel surfaces - Spranger, Felix; Schirdewahn, Stephan; Kromm, Arne; Merklein, Marion; Hilgenberg, Kai (Journal of Laser Applications, 2020)
The control of friction and wear is a major concern in many industrial applications. A promising method for tailored surface modification is the so-called laser implantation technique. This method combines surface texturing and material optimization in one processing step by a localized dispersing of hard ceramic particles using pulsed laser radiation. Wear resistant, protruding micrometric features (implants) with defined geometry can be created in a deterministic pattern where needed on highly stressed surfaces, i.e., on forming or cutting tools. However, in order to maintain the implants over the tool's lifetime, a suitable selection of hard ceramic particles is a prerequisite. They must provide a defect-free metal matrix composite with a high share of homogeneously distributed particles and, especially, high implant hardness. In this study, TiN, TiC, and TiB2 hard particles were compared as implant materials for the first time. By a systematic variation of pulse power and pulse duration, their dispersing behavior and influence on the material properties of AISI D2 tool steel were investigated. Although all powder materials had grain sizes smaller than 10 mu m, it was possible to disperse them by pulsed laser radiation and to obtain defect-free protruding implants. The highest share of dispersed particles (similar to 64%) was observed for TiB2. By scanning electron microscopy and energy dispersive x-ray spectroscopy, it was also shown that a significant share of the preplaced particles was dissolved by the laser beam and precipitated as nanometer sized particles within the matrix during solidification. These in situ formed particles have a decisive influence on the material properties. While the TiN and TiC implants have shown maximum hardness values of 750 and 850 HV1, the TiB2 implants have shown the highest hardness values with more than 1600 HV1. By x-ray diffraction, it was possible to ascribe the lower hardness values of TiC and TiN implants to high amounts of retained austenite in the metal matrix. By implanting TiB2, the formation of retained austenite was successfully suppressed due to the in situ formation of TiC particles, which was proven by electron backscatter diffraction. In conclusion, all the implant materials are basically suitable for laser implantation on AISI D2 tool steel. However, TiB2 has shown the most promising results.
CRIS-Team WoS Importer:2020-05-22

On the inverse identification of Lankford coefficients using geometrical changes under quasi-biaxial loading - Graser, Matthias; Lenzen, Matthias; Merklein, Marion (International Journal of Material Forming, 2019)
Finite element simulation has become an important tool of process and production design in various fields, especially in the automotive industry. The calculation of forming processes in the early concept phase of new cars allows virtual adaptions, which can reduce costs of later phases in the product development significantly. Therefore, the precise characterization and modelling of the material behavior is necessary to ensure a robust and reliable numerical process design. The mechanical properties of numerous materials are highly influenced by the rolling or extrusion direction in the production process. This necessitates the characterization of materials in different loading directions. However, depending on the dimensional aspects of the semi-finished product, the manufacturing of specimens can be challenging or even impossible. Thus, in this investigation, an innovative, indirect approach for the identification of the Lankford coefficient in transversal direction is presented. Based on numerical and experimental data of layer compression tests the Lankford coefficient is determined by inverse modelling of the resulting specimen contour. Due to the characteristics of the layer compression test, it can even be used for semi-finished products with small transversal dimensions like extruded profiles. The presented methodology is on the one hand verified by conventional uniaxial tensile tests for aluminum as well as steel blank material. On the other hand it is used to determine Lankford coefficients for an aluminum extrusion hollow profile and the inversely identified material model is validated by comparison of strain distributions of experimental and numerical square tube bending tests.
CRIS-Team Scopus Importer:2019-08-06
Keywords: Inverse parameter identification; Lankford coefficient; Layer compression test; Material modelling

On the location of antennas for treatment planning in hyperthermia - Hutterer, Angelika; Jahn, Johannes (Or Spectrum, 2003)
In this paper we investigate how to determine optimal locations of the microwave antennas being circularly ordered in a hyperthermia device. The heated area containing the tumor should have minimal volume. Based on a simple geometric model for the two and three dimensional case we develop algorithms for the computation of these volumes and present numerical results for the optimal location
UnivIS-Import:2015-03-09:Pub.2003.nat.dma.pama21.onthel
Keywords: Antenna optimization; Cancer medicine; Nonlinear programming

On the tribological influence of coatings in cold forging - Andreas, Kolja; Merklein, Marion (Proc. 11th Int. Conf. THE "A" Coatings in Manufacturing Engineering, 2014)
LFT Import::2019-08-05 (2047)

On the uniaxial compression behavoir of regular shaped cellular metal - Öchsner, A.; Lamprecht, Klaus (Mechanics Research Communications, 2003)
LFT Import::2019-07-15 (945)

On the Way to Real-time Simulation of Incremental Laser Beam Bending - Komlodi, Attila; Otto, Andreas; Geiger, Manfred (Laser Assisted Net shape Engineering 4 - Proceedings of the LANE 2004, 21.-25. September 2004, Erlangen, Germany, 2004)
LFT Import::2019-08-05 (1091)

Optical forming analysis of functional components manufactured in an orbital forming process - Hetzel, Andreas; Sawodny, Annette; Lechner, Michael; Merklein, Marion (XL. Colloquium on Metal Forming, 2022)
Global challenges like an increased sustainability or reduced carbon dioxide emissions demand for efficient process solutions and innovative products. Functional integration and lightweight design propose one way to meet these challenges, nevertheless resulting in increased component complexity as well as long process chains, bringing conventional manufacturing processes to their limits. The process of orbital forming can be applied to efficiently manufacture functional components with varying sheet thickness, like in gear systems. This process is assigned to Sheet-Bulk Metal Forming (SBMF), featuring multi-dimensional stress and strain states in the sheet metal. In order to increase the forming behaviour, the control of the material flow was identified as major challenge in previous research. Therefore, this contribution focuses on the optical forming analysis of the functional components, to increase the understanding regarding the cause-effect relations on the indicated material flow. The components are manufactured out of the high-strength tempered steel 51CrV4 with an initial sheet thickness of 2.0 mm and feature different rotational and cyclic-symmetric elements. The aim of this investigation is the establishment of an extended process understanding on the interdependencies between an occurring three-dimensional material flow and the forming in the context of SBMF processes, in order to increase formability and quality of the manufactured parts.<br
Keywords: sheet-bulk metal forming; orbital forming; forming analysis; sheet metal; functional component

Optical In-Process Sensor for Laser Beam Welding - Hohenstein, Ralph; Dietrich, Simon; Otto, Andreas (Proceedings of the LANE 2007, 2007)
LFT Import::2019-08-05 (1415)

Optimierte Produktqualität und Werkzeuglebensdauer durch stochastische Simulation - Geiger, Manfred; Engel, Ulf; Völkl, Ralf (Zeitschrift für wirtschaftlichen Fabrikbetrieb, 2003)
LFT Import::2019-07-15 (964)

Optimierungsstrategien zur Verbesserung der Lebensdauer von Umformwerkzeugen - Geiger, Manfred; Hänsel, Matthias; Sobis, Tomasz; Engel, Ulf (Prozeßsimulation in der Umformtechnik, 1993)
LFT Import::2019-07-15 (400)

Optimisation of Specimen's Geometry for Characerisation of Plastic Yielding - Geiger, Manfred; Merklein, Marion; Hußnätter, Wolfgang (Proceedings of the 8th ESAFORM Conference on material forming, 2005)
LFT Import::2019-08-05 (1170)

Optimization of the heat treatment layout and blank outline of THTB - Lechner, Michael; Kuppert, Andreas; Hagenah, Hinnerk; Merklein, Marion (Key Engineering Materials, 2013)
Tailored heat treated blanks (THTB) is the generic term for an innovative approach to enhance the formability of blanks made out of high strength steel or aluminum alloys. Key idea of the technology is the adaption of the mechanical properties by a local heat treatment. Based on the new property distribution, the material flow during the forming operation can be improved and the forming limit can be enhanced. In comparison to conventional temperature assisted approaches the forming is performed at room temperature and therefore all advantages of a cold forming process can be used. Most challenging within the application is the definition of the heat treatment layout. Up to now the layout is dimensioned in a time-consuming trial and error procedure. In this paper a new approach for the automatic optimization of the heat treatment layout and the blank outline is presented. Copyright © 2013 Trans Tech Publications Ltd.
LFT Import::2019-07-29 (1856)
Keywords: Enhancement of formability; Optimization; Tailored heat treated blanks

Optimization of tool and process design for the cold forging of net-shape parts by simulation - Kroiss, Thomas; Engel, Ulf (Process Machine Interactions, 2012)
LFT Import::2019-07-29 (1846)

Optimization on Hot-Forming Technologies - New Tool Designs and Alternative Heating Technologies for Tailored Properties - Kopp, C.; Griesbach, B.; Bader, K.-M.; Freudenberg, P.; Hezler, Christian; Russ, F. (Proceedings Tools and Forming, 2011)
LFT Import::2019-08-05 (1771)

Optimized Process Control Strategy for the Laser Cutting and Welding of Complex Hydroforming Parts - Blankl, Andreas; Kreis, Oliver; Merklein, Marion (Proceedings of the Lasers in Manufacturing, 2005)
LFT Import::2019-08-05 (1167)

Optimizing Laser Forming by FEM-Simulation - Geiger, Manfred; Holzer, Stefan; Vollertsen, Frank (Annals of the German Academic Society for Production Engineering, 1995)
LFT Import::2019-08-05 (545)

Optimizing Systems for Laser Beam Welding. - Deinzer, Günter; Otto, Andreas; Hoffmann, Peter; Geiger, Manfred (Proceedings of the CIRP, 1995)
LFT Import::2019-08-05 (515)

Optische 3D-Konturerfassung und on-line Biegewinkelmessung mit dem Lichtschnittverfahren - Heckel, Werner (1995)
The aim of the thesis is the development of an in-process measurement of the bending angle in order to establish a control system for air bending. For fundamental investigations in configuration, calibration and evaluation a 3-D coordinate measuring system with flexible beam guiding system was built up. A strategy for automatic calibration based on the photogrammetric method of Direct Linear Transformation was developed. For in-process measurement of the bending angle a special tool (patent pending) was developed. The procedures for evaluation and calibration of the measuring system were adapted to the conditions in industrial use. The special tool allows in-process measurement of the bending angle both during every stage of the bending process and after release of the workpiece. The special tool allows direct control of the bending angle applying incremental correcting bends. The working accuracy achieves ± 0,2° regardless of the material properties. Every part turns out well after 1-3 correcting bends without any test bend

Optische Prozess-Sensorik für die Onlinediagnostik und -regelung in der Lasermaterialbearbeitung - Otto, Andreas; Dietrich, Simon (Tagungsband zur WLT Laser Summerschool, 2006)
LFT Import::2019-08-05 (1299)

Orbital Forming of Tailored Blanks for Industrial Application - Hetzel, Andreas; Lechner, Michael (Sheet Bulk Metal Forming, 2021)
The efficient process of orbital forming can be used to manufacture functional components with a varying sheet thickness profile. It is characterized by a tumbling movement of the die and counterpunch, thus reducing the contact area between work piece and tool as well as the maximum forming force significantly. Within the project A1 of the Transregional Collaborative Research Centre (TCRC 73), the process of orbital forming has been investigated fundamentally. The control of the material flow to increase the maximum form filling could be identified as major challenge. The objective of this transfer project is the enlargement of the forming limits in comparison to conventional orbital forming by developing and applying tailor-made process and heat treatment strategies for industrial relevant steel and aluminum alloys. For the purpose of a transfer to industrial application, a demonstrator geometry with a varying sheet thickness profile is defined. Main aspects of the investigation are the resulting geometric and mechanic properties and the possibility to enlarge the forming limits. The final geometric shape is realized by applying different cutting operations. An industrial application is evaluated by assembling the demonstrator to a near-series clutch disc and analyzing the functional behavior.<br
Keywords: Sheet-Bulk Metal Forming; Orbital Forming; Material Flow Control

Orbital forming of tailored blanks from sheet metal - Merklein, Marion; Plettke, Raoul; Opel, Simon (CIRP Annals - Manufacturing Technology, 2012)
LFT Import::2019-07-29 (1787)
Keywords: Incremental bulk forming; Sheet metal; Simulation

Orbital forming of tailored blanks with two-sided local material thickening - Hildenbrand, Philipp; Lechner, Michael; Vogel, Manfred; Herrmann, H.; Merklein, Marion (International Journal of Advanced Manufacturing Technology, 2018)
Economic and ecological demands like saving resources and improved material efficiency can be achieved by the application of process adapted semi-finished parts, so-called tailored blanks, for the manufacturing of for example gearings or synchronizer rings. Functional components require the locally restricted distribution of an adequate amount of material at defined positions in order to properly form functional elements like gearings or carriers. As these elements can be formed on one or both sides of the component, an appropriate material provision on one or both sides of the sheet metal is necessary. Having material thickenings on two sides lead to the interaction between both sides for example with regard to the maximum die filling. One process to produce tailored blanks is orbital forming. While manufacturing these tailored blanks with a local material thickening on one side of the sheet metal is state-of-the-art, the realization of these tailored blanks on both sides has not been investigated yet. In this paper, the results regarding the manufacturing of tailored blanks with a two-sided local material thickening will be presented for the first time. By analyzing three different tailored blank geometries, the influence of the interactions of two-sided material thickenings will be investigated. The results will be evaluated in terms of the resulting geometrical and mechanical properties.
LFT Import::2019-07-29 (2310)
Keywords: Forming; Orbital forming; Sheet-bulk metal forming; Tailored blank

Overview on sheet-bulk metal forming processes - Merklein, Marion; Tekkaya, A. E.; Brosius, A.; Opel, Simon; Koch, Johannes Peter Karl (Proceedings ICTP 2011, 2011)
The process class sheet-bulk metal forming (SBMF) provides the manufacturing of local functional features in the magnitude of the sheet thickness through a controlled material flow. This paper gives an overview on the technology and application of various bulk forming operations on sheet metals. Based on the variety on the processes a classification by the specific kinematics is developed. The tools movement can be divided in a linear and rotational tool motion. It has been shown that the intended geometry is nearly impossible to achieve using conventional tooling systems even applying extremely high forces. Therefore multi-stage forming operations and several combinations of the presented SBMF processes often are used. An overview of existing SBMF operations in literature will be given. In addition some numerical studies and physical experiments will be shown, that can be used for analysis of materials flow, the interaction of tooling systems and the material flow within SBMF processes. © 2011 IBF (RWTH Aachen) & IUL (TU Dortmund).
LFT Import::2019-08-05 (1727)
Keywords: Process Control; Sheet-bulk metal forming; Simulation

Parameters Influencing Adhesive Wear Behavior within Hot Stamping Operations - Wieland, Michael; Merklein, Marion (Proc. 5th Int. Conf. Hot Sheet Metal Forming of High-Performance Steel, 2015)
LFT Import::2019-08-05 (2097)

Path Planning for a Kinematic Section Bending Process. - Geiger, Manfred; Arnet, Horst; Vollertsen, Frank (Production Engineering, 1997)
LFT Import::2019-07-15 (712)

Patterning of Circuitry on Tree-Dimensional Molded Interconnected Devices Using Focused Laser Radiation - Geiger, Manfred; Roth, Stephan; Eßer, Gerd (Production Engineering, 1998)
LFT Import::2019-07-16 (1595)

Perfomance of Hot Forging Tools built by Laser Metal Deposition of Hot Work Tool Steel X37CrMoV5-1 - Junker, Daniel; Hentschel, O.; Schramme, R.; Schmidt, M.; Merklein, Marion (Laser in Manufacturing Conference 2017, 2017)
LFT Import::2019-08-05 (2268)

Performance of Silicon Punches for Microblanking of Thin Metal Foils - Hildering, Sven; Merklein, Marion; Engel, Ulf (4th International Conference on Nanomanufacturing (nanoMan), 2014)
LFT Import::2019-07-29 (2024)

Photonic crystal fibers for generating three-photon states - Chekhova, Maria; Cavanna, Andrea; Taheri, Michael; Okoth, C.; Jiang, X.; Joly, Nicolas; Russell, Philip St. John (2017 Conference on Lasers and Electro-Optics, CLEO 2017 - Proceedings, 2017)
Direct decay of pump photons into triplets is an interesting but not-yet-realized nonlinear effect. We are exploring two approaches using photonic crystal fibers: a gas-filled hollow-core PCF and the recently designed hybrid solid-core PCF.
CRIS-Team Scopus Importer:2023-03-27

Physical and Numerical Modelling of the Buckling Mechanism. - Holzer, Stefan; Arnet, Horst; Geiger, Manfred (Manufacturing Systems, 1995)
LFT Import::2019-07-15 (566)

Physical modeling of surface asperities for basic investigation on tribology in cold forging - Weidel, Stephan (Proceedings of the 5th Seminar on Precision Forging, 2009)
LFT Import::2019-08-05 (1563)

Physical modeling of surface asperities - the impact of liquid lubricant on the real contact area - Weidel, Stephan; Engel, Ulf; Geiger, Manfred (Proceedings of the 9th International Conference on Technology of Plasticity ICTP, 2008)
LFT Import::2019-08-05 (1539)

Pin Extrusion for Mechanical Joining from Orbital Formed Tailored Blanks with Local Material Pre-Distribution - Römisch, David; Hetzel, Andreas; Wituschek, Simon; Lechner, Michael; Merklein, Marion (Journal of Manufacturing and Materials Processing, 2022)
Pin extrusion is a common process to realise pin structures in different geometrical dimensions for a subsequent joining operation. Nevertheless, the process of pin extrusion offers process limits regarding sheet thinning as a consequence of the punch penetration depth into the sheet. Thereby, cracks at the residual sheet thickness can occur during strength tests, resulting in a failure of the complete joint due to severe thinning. Therefore, measures have to be taken into account to reduce the thinning. One possibility is the application of orbital formed tailored blanks with a local material pre-distribution, which allows a higher sheet thickness in the desired area. Within this contribution, the novel approach of a process combination of orbital forming and pin extrusion is investigated. To reveal the potential of a local material pre-distribution, conventional specimens are compared with previously orbital formed components. Relevant parameters such as the residual sheet thickness, the pin height as well as the average hardness values are compared. The results show a significant positive influence of a local material pre-distribution on the residual sheet thickness as well as the resulting pin height. Furthermore, the strain hardening during orbital forming can be seen as an additional advantage. To conclude the results, the process limits of conventional pin extrusion can be expanded significantly by the application of specimens with a local material pre-distribution.<br

Planarisierung miniaturisierter Nb-Schaltungen durch chemisch-mechanisches Polieren(CMP) - Neuhaus, M.; Götz, M.; Eßer, Gerd; Scherer, T.A.; Jutzi, W. (Frühjahrstagung der Deutschen Physikalischen Gesellschaft DPG, 1998)
LFT Import::2019-08-05 (1631)

Planning and Control of Laser Forming Applications - Hagenah, Hinnerk; Plettke, Raoul; Geiger, Manfred (Proceedings of the 39th CIRP International Seminar on Manufacturing Systems, 2006)
LFT Import::2019-08-05 (138)

Planning of Handling Operations for Complex Bending Parts - Geiger, Manfred; Vormann, Bodo (Production Engineering, 1995)
LFT Import::2019-07-15 (558)

Planning the use of high-power excimer laser for psoriasis treatment - Hagenah, Hinnerk; Schmidt, Michael; Klämpfl, Florian (Manufacturing Systems and Technologies for the New Frontier - The 41st CIRP Conference on Manufacturing Systems, 2008)
LFT Import::2019-08-05 (1516)

Planungssystem für das Handhaben komplexer Blechbiegeteile - Geiger, Manfred; Vormann, Bodo (Bänder, Bleche, Rohre, 1994)
LFT Import::2019-07-15 (608)

Plastic flow and its control in sheet-bulk metal forming of thin-walled functional components - Merklein, Marion; Löffler, Maria; Schneider, Thomas (CIRP Annals - Manufacturing Technology, 2015)
This paper deals with a manufacturing process for sheet metal components with integrated functional elements by sheet-bulk metal forming. In a single forming stage a cup-shaped base body with thin-walled features is deep drawn and its geometry is calibrated by upsetting. The fundamental numerical and experimental investigations include the analysis of the die filling behaviour, part geometry and mechanical properties due to strain hardening with respect to the variation of the blank layout, forming force and material strength. Finally, the process limits are identified and approaches for their enhancement by the application of tailored surfaces are presented.
LFT Import::2019-07-29 (2088)
Keywords: Forming; Processing; Surface modification

Post-Treatment of Direct Metal Laser Sintered Parts by Infiltration Process - Dueck, J.; Niebling, Frank; Neeße, T.; Geiger, Manfred (Space Challenge in the 21st Century, 2003)
LFT Import::2019-07-15 (967)

Potential der Laserstrahlbearbeitung zur - Geiger, Manfred; Becker, Wolfgang; Pohl, M.; Schaus, M. (Tagungsband der Werkstoffwoche 96, Symposium 5, Werkstoffe für die Fertigungstechnik (1997), 1996)
LFT Import::2019-08-05 (669)

Potentiale der Kombination von Umformtechnik und additiver Fertigung in hybriden Prozessketten - Papke, Thomas; Huber, F.; Hagenah, Hinnerk; Schmidt, M.; Merklein, Marion (6. Industriekolloquium des Sonderforschungsbereichs 814 - Additive Fertigung, 2018)
LFT Import::2019-08-05 (2351)