Wear mechanisms on multiphase Al2O3 ceramics during running-in period in unlubricated oscillating sliding contact

Commercially available, slightly porous monolithic alumina was modified usi ng CO2-laser irradiation by embedding zirconia, titanium nitride and tungst en carbide. The thickness of the modified surface layers was 550 mum after laser treatment and the composition of the multiphase microstructures depen ded on the laser process and the additives used. Tribological tests were ca rried out on the ceramics using a laboratory tribometer in unlubricated, os cillating sliding contact at room temperature against alumina halls. The we ar mechanisms during running-in were analysed by short-time tests and studi es of the worn surfaces: by SEM.