Journal article


Friction Adjustment within Dry Deep Drawing by Locally Laser Textured Tool Surfaces


Publication Details
Author(s): Häfner T, Heberle J, Dobler M, Gränitz M, Alexeev I, Schmidt M
Publisher: Trans Tech Publications
Publication year: 2015
Journal issue: Vol. 639
Pages range: 57-64
ISSN: 1013-9826
Language: English

Abstract

In deep drawing processes sustainability can be increased and processing steps can be omitted by abolishing any lubricants. Tailored tools with locally textured surfaces offer a possibility to compensate higher strains caused by the changed tribological system. Ultrashort pulsed laser machining is an advantageous approach to generate surface features. Thus, very hard and brittle materials can be processed inducing negligible heat affected zones so that the surrounding tool material keeps its initial properties. The material-dependent process parameters for efficient picosecond laser structuring are applied. The effects of features with single feature sizes in the range of 100 µm to 500 µm on friction of the tribological pairing are presented. The dependencies of the friction coefficient on the properties of the micro features - the geometry, the shape, the density and the orientation - are investigated by using a ring-on-disc-tribometer. The ring representing the tool is made out of the cold work steel 1.2379. The zinc-coated deep-drawing steel DC04 is used as disc respectively workpiece material. During the ring-on-disc-tests a constant contact pressure of 2.1 MPa and a mean sliding velocity of 100 mm/s are applied. To obtain the significant influences of micro features on friction, screening tests by varying the parameters according to the Shainin method are carried out. Because of the stochastically occurring high wear observed in reference experiments a changed methodology of ring-on-disc-tests is proposed. Applying this method the effects of textured ring surfaces on friction coefficient of steel-zinc-sliding are evaluated and compared to untextured rings. The latter are tested non-lubricated as well as with lubrication. The screening tests show that the feature orientation is the significant parameter influencing the friction. Selecting this parameter together with the feature density the friction coefficient can be adjusted with regard to untextured surfaces.



How to cite
APA: Häfner, T., Heberle, J., Dobler, M., Gränitz, M., Alexeev, I., & Schmidt, M. (2015). Friction Adjustment within Dry Deep Drawing by Locally Laser Textured Tool Surfaces. Key Engineering Materials, Vol. 639, 57-64.

MLA: Häfner, Tom, et al. "Friction Adjustment within Dry Deep Drawing by Locally Laser Textured Tool Surfaces." Key Engineering Materials Vol. 639 (2015): 57-64.

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