Effect of temperature and sliding velocity on TiN coating wear

Abstract

Dry sliding wear experiments at specific temperatures ranging between 25 and 500 °C were conducted on a PVD (reactive ion plated) TiN coating deposited onto an austenitic stainless steel substrate. The coating was worn against high-speed steel pins using a pin-on-disc sliding configuration at a low contact load (10 N) and various sliding speeds. Three wear regimes were identified: (1) at low temperatures and sliding speeds up to ~ 1.0 m s −1, there was minimal damage to the ion-plated TiN and the formation of a protective iron oxide transfer layer on the TiN surface; (2) at temperatures in the ~200–450 °C range, polishing of the TiN occurred, accompanied by increased wear rates as speed was increased; (3) above ~450 °C ductile deformation and failure of the coating occurred. Steel pin wear rates dropped significantly and the wear track was coated with a titanium/iron oxide transfer layer. The wear rate data are summarised in map form on temperature vs. sliding speed axes and discussed together with corresponding SEM, EDS and optical metallographic evidence.