Temperature effects on the tribological behavior of alumina reinforced with unidirectionally oriented SiC whiskers

In the present study, the influence of temperature on the tribological behavior of alumina reinforced with SiC whisker addition up to 20 vol.% is presented. Wear tests were performed at selected temperatures with alumina composites prepared by a modified tape casting method. Above a 673 K wear test temperature, the wear and frictional characteristics behaved differently compared with tribological behavior at 403 K. The results of this study indicate that as the temperature increased, the reinforcement effect of the unidirectionally oriented SiC whisker increased and the grain size effect was decreased. The effect of whisker orientation on friction and wear characteristics at the higher temperature was not dependent on test temperatures. The highest wear rate was obtained with a SiC whisker oriented parallel to the tape casting direction at all tested temperatures. The friction and wear mechanism of alumina composites reinforced with SiC at a high temperature is discussed based on SEM observations of worn surfaces and energy dispersion X-ray analysis.