Residual Stress Distribution in PVD-Coated Carbide Cutting Tools - Origin of Cohesive Damage



PVD-coatings for cutting tools mean a  substantial progress fo tool  lifetime and cutting  conditions. Such tools, however, hold the risk  of  cost intensive  sudden process breaks as a result of cohesive damage.This damage mechanism does not consist of  a coating  adhesion  problem, but it can be traced  back to the residual stress distribution in coating and substrate. This paper shows, how residual stresses develop  during the process chain  for  the  manufacturing of  PVD-coated carbide cutting tools. By means of different methods  for residual  stress determination it is shown that the distribution of residual stresses  within the tool finally is responsible for the risk of cohesive tool damage.