Effect of Material Combination on the Wear Properties of Ceramics

In the previous paper, sliding wear properties of oxide ceramics was evaluted using an indentation fracture model in which the effect of roughness at the frictional surface was assessed. This model was tested for non-oxide ceramics at various vertical load, and the transition of wear properties was studied with a pin-on-disk tester using SiC, Al2O3 and ZrO2 as pin, and SiC, Si3N4 and Al2O3 as disk. Wear increased by more than ten times depending on the combination of pin and disk materials. When the frictional surface was smoothed by the increased vertical load, the wear was independent of the load. To explain this phenomenon, an equation was derived to estimate quantitatively the effect of a roughness at the frictional surface on wear. Hence, the wear transition was estimated for the sliding surface, of which roughness depends on the vertical load. However, the effect of material combination on the wear was not able to be explained by this equation completely. This result suggested that the transition of wear by material combination was took place by the changed wear mechanism.