Friction and Wear Behaviors of Ceramics-Cemented Carbide Couples (Part III)

Abstract

The wear resistance of single crystal of alumina is determined as a function of crystallographic orientation with respect to the rubbing plane and direction. In this case, it is usually found that there are a typical anisotropy of the wear between basal and prismatic planes, and some evidences of plastic flow at the wear surface planes in the wear test. Also, the wear anisotropy in single crystal of alumina depends upon contact load and sliding speed. Since c-axis of alumina crystal is preferably oriented along the pressing direction during hot pressing, in this paper, the effect of this preferred orientation on the wear resistance of hot pressed alumina was compared with the wear anisotropy in the single crystal. From the microstructural observations and some other experimental results, it was shown that the wear mechanism of hot pressed polycrystalline alumina can be understood from that of the single crystal.