The friction and wear properties of self-mated zirconia (ZrO2) in unlubricated sliding contact were investigated by using a pin/disk friction machine, From the obtained results and the morphologies of frictional surfaces observed by SEM and particle size distribution of wear particles, the friction and wear mechanism of ZrO2 pin slide against ZrO2 disk was discussed, In this system, the average friction coefficient was almost independent of the load applied, but the wear amount increased with an increase of the load, The wear particle sizes became larger with increasing sliding time and load applied, It is found that the friction and wear mechanism of ZrO2 is dominated with the formation, delamination and fracture of surface him transferred on frictional surfaces by friction and adhesion, and that they are influenced by friction heat and the load applied.
