Abstract
Because of the unique combination of high hardness, high heat resistance, and chemical inertness, ceramic materials are serious candidates for the tribological materials used under sever operating conditions. In this study unlubricated wear tests were carried out to investigate the effect of microstructure on wear properties of structural ceramics (silicon nitride, sialon and alumina ceramics) with diverse microstructures. For alumina ceramics wear rate increased with microstructure change from fine equiaxed grain morphology to coarse and/or anisotropic morphology, consistent with previous works reported by many researchers. On the contrary, for silicon based nitrogen ceramics such as sialons and silicon nitrides, wear rate decreased with microstructure change from fine equiaxed grain morphology to fine bimodal, accompanied with an increase of fracture toughness; but it increased when microstructure became coarse bimodal.
