Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Influence of surface integrity on the behavior of cold forging tools



Datum: 30.11.2015


Author


Reporter

  • Prof. Dr.-Ing. habil. M. Merklein
  • Prof. Dr.-Ing. B. Denkena

The thesis investigated the interdependencies between tool machining, surface integrity and the resulting behavior of cold forging tools. Within the studies conventional process chains as well as adapted process combinations were comparatively analyzed. Cemented carbides and tool steel were applied as tool materials in order to prove universal validity of the results. In laboratory tests a distinct influence of the size of the surface defects and the near surface residual stresses on the fatigue behavior could be detected. Regarding the tribological behavior, the topography of the tool surface is crucial. From the gained functional correlations between surface properties and tool behavior, process chains were derived which lead to favorable tool behavior. Three possibilities were identified as useful adaptions: the substitution of electrical discharge machining by grinding during machining of tool geometry, the integration of combined blasting and shot peening in the process chain as well as a shift from manual polishing to automated polishing. In serial production tests the transferability of the gained functional correlations under laboratory conditions to industrial production could be proven.