Integration von Werkstoffermüdungseffekten

Integration of fatigue of materials into the wear simulation of forming tools

 

Motivation

Light-weight constructions cause more and more the application of high-strength materials. The consequences are tools, which wear out much faster. Along with more wear come higher costs caused by shorter durability, laborious reworks and longer downtimes of the forming machines. Optimisation of tool coating and lubrication is commonly done not till wear appears.

Figure 1: tool with wear at locations with high loads (source: Daimler AG)
Figure 1: tool with wear at locations with high loads (source: Daimler AG)

Objectives

With regard of fatigue of materials within the wear simulation of forming tools, the development of forming tools is to be more adjusted to wear problems even in the design stage in order to avoid costly subsequent optimisation.

Procedure of solution

Various parameters like relative velocity of friction partners, surface pressure, intermittently loads and temperature have influence to tool wear. To isolate the influences of these parameters, they are tested in strip-draw tests. Thus, conditions of press plants can be reproduced while single parameters can be varied. Wear work is kept constant through all experiments.

Figure 2: principle of strip-drawing test
Figure 2: principle of strip-drawing test

After the practical tests, the results are to be integrated into the wear software REDSY in corporation with utg (Lehrstuhl für Umformtechnik und Gießereiwesen) in Munich. In the end, a validation of the results by means of real processes will be done.