FRICTION AND WEAR PROPERTIES OF PARTIALLY-STABILIZED ZIRCONIA WITH SOLID LUBRICANT

The friction and wear properties of partially stabilized zirconia (PSZ ) lubricated with copper powder, copper film or CuO film were studied. The wear rate of unlubricated PSZ increased with normal loads. When l oads were over 20 N, a transition from mild to severe wear (wear rate > 1 X 10(-5) mm3 (Nm)-1) occurred. The CuO film, which was formed by h igh-temperature chemical diffusion, effectively prevented PSZ from sev ere wear. Even at a load of 35.6 N the wear rate was essentially zero. It was very difficult to measure any wear by the surface profilometry technique used in the study. The friction coefficients of PSZ were re duced from 0.40 to 0.20, 0.17 and 0.14 for copper powder, copper films and CuO films, respectively. A scanning electron microscope was used to study the mechanisms of friction and wear of PSZ.