Mapping wear mechanisms of TiC/Ti composite coatings

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 1.5 m s−1, and the normal load was varied from 10 to 50 N. 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.