Friction and wear characteristics of fine ceramics by pin-on-disk and journal sliding bearing tests (part 2): in water

With the aim of obtaining fundamental information concerning friction and wear behaviors of fine ceramics under water-lubrication condition, we undertook pin-on-disk and journal bearing tests using frictioning pairs of the same materials for Sialon, ZrO"SUB 2" and Al"SUB 2" O"SUB 3" . In the case of Sialon frictioning pair, significant decrease of friction coefficient with increasing sliding distance was observed, while progress of wear continued even after the friction coefficient reached to comparatively low level under condition of high load intensity. In the case of ZrO"SUB 2" frictioning pair, significant correlation was observed between wear and friction coefficient; wear virtually ceased at friction coefficient 0.4. On the other hand, wear of Al"SUB 2" O"SUB 3" progressed virtually independent of load intensity. From this experimental evidence, we concluded that major mechanism of wear under investigated range for Sialon must be tribochemical reaction, that for ZrO"SUB 2" in comparatively high load range to be wear associated with phase transition and that for Al"SUB 2" O"SUB 3" to be mechanical wear. (from Authors)