Tailored tool surfaces for friction and wear reduction in sheet metal forming

Tailored tool surfaces for friction and wear reduction in sheet metal forming

 

Motivation

Using hardened and coated tool surfaces or structured sheet metal (workpiece) the friction and wear in deep drawing can be optimized. Especially in the last case two different mechanisms are working: On the one hand lubricant pockets help to build up a hydrostatic fluid pressure. On the other hand surface elevations reduce the real contact surface. In this case experiments proved that the microstructuring of tool surfaces show great potential to reduce friction and wear, too.

 

Objective

It is the aim of this project to reduce friction and wear in deep drawing by tailored (microstructured) tool surfaces with the help of machine hammer peening. In this respect the coefficient of friction and the appearing wear behavior is investigated and compared to the state of the art.

 
Figure 1: Micro structuring with adjusted hammering heads
Figure 1: Micro structuring with adjusted hammering heads
 

Approach

With the help of experimental and numerical approaches, the surface structures are designed, produced by machine hammer peening and characterized. Afterwards coefficients of friction and the wear behavior of different structures are determined. In this case it is of interest whether lubricant pockets or a reduced real contact surface as advantageous for deep drawing processes. Finally the most promising results are examined under industrial conditions. The derivation of guidelines completes the project.

Acknowledgment

The PtU would like to thank the der European Research Association for Sheet Metal Working (EFB) and the following companies for their support.

  • Daimler
  • Volkswagen
  • FILZEK TRIBOtech
  • Oerlikon Balzers VST
  • Seidel
  • Siebenwurst Werkzeugbau
  • Römheld+Moelle
  • Rhenus Lub