Mapping wear mechanisms for TiC/Ti composite coatings

In this work, a fundamental study of the wear transition regimes was carried out for a pin-on-disk sliding couple, involving hardened gauge plate steel (disks) and titanium base titanium carbide composite coatings (pins). The coating was carried out by a TIG process. The sliding speed was varied from 0.38 to 1.5m s-1, and the normal load varied from 10 to 50N. Dry sliding wear behaviour of hardened gauge plate disks was characterized by abrasive-oxidative wear at lower normal loads while adhesive-oxidative wear predominated at high normal load with iron oxide transfer to Ti base TiC composite coatings pins. In contrast, micro-polishing and adhesive wear predominated for the CP-Ti base TiC composite coatings pins along with very mild abrasive wear. A tribo-system approach has been adopted to investigate the wear behaviour of TiC coatings and hardened gauge plate against each other. Wear maps have been constructed to represent the wear mode transitions and the observed wear mechanisms have been discussed.