Mapping wear mechanisms of TiC/Ti composite coatings

Abstract

In this work, a fundamental study of the wear transition regimes with respect to sliding speed and normal load was carried out for a pin-on-disk sliding couple, involving hardened steel (disks) and titanium base titanium carbide composite coatings (pins). The coating was deposited using a Tungsten Inert Gas (TIG) welding torch melting process. The sliding speed was varied from 0.38 to 1.5ms−1, and the normal load was varied from 10 to 50N. Dry sliding wear behavior of the disks was characterized by abrasive–oxidative wear at lower normal loads while adhesive–oxidative wear predominated at higher loads with iron oxide transfer to the TiC composite coated pins. In contrast, micro-polishing and adhesive wear predominated the TiC composite coatings pins along with very mild abrasive wear in evidence. However, the wear regime depended on the conditions with a range of transitions observed over the sliding speeds and loads tested. Wear maps have been constructed to represent the wear mode transitions and the observed wear mechanisms have been discussed.