WEAR OF SOME ADVANCED CERAMICS UNDER A SHARP INDENTER IN UNIDIRECTIONAL SLIDING

The wear of reaction-bonded SiC (RSSiC), dense silicon nitride (DSN), tetragonal zirconia ZrO2(t), and alumina-titanium nitride (Al2O3-TiN) composites have been studied under a sliding diamond indenter having a n included angle of 90-degrees and a tip radius of 6 mum at a sliding speed of 8 mm/s. The relative wear resistance as measured from the tra ck diameter was in the order DSN > Al2O3-TiN > RSSiC > ZrO2(t). The tr ack width showed a straight-line relationship with the square root of load, implying that lateral cracking was responsible for the wear. The wear rates decreased with load and varied from 1 x 10(-5) to 2 x 10(- 5) mm/(m.g) for the above ceramics. The wear rate increased sharply as the velocity increased over 1 m/min at a load of 300 g and above due to frictional heat generated because of the work of sliding.