Formation of smooth wear surfaces on alumina ceramics by embedding and tribo-sintering of fine wear particles

The role of the wear particles for the formation of various wear surfaces, especially mirror-like wear surface, was investigated based on detailed observations of wear surfaces and by introduction of two types of model experiments. Smooth wear surfaces (Rmax<1 μm) are formed by two processes of micro-wear of asperity peaks of alumina grains and filling in surface hollows with fine wear particles. In order to form the mirror-like wear surface (Rmax<0.1 μm) of alumina, tribo-sintering of wear particles is necessary in addition to necessary condition for smooth surface formation introduced in previous works [K. Adachi, K. Kato, N. Chen, Wear 203–204 (1997) 291–301; K. Adachi, K. Kato, E. Inoue, R. Takizawa, Proc. Int. Trib. Conf. Yokohama (1995) 415–420]. Finally, friction conditions which can give mirror-like wear surfaces as a result of wear are proposed by analyses from both the view points of fracture mechanics [K. Adachi, K. Kato, N. Chen, Wear 203–204 (1997) 291–301; K. Adachi, K. Kato, E. Inoue, R. Takizawa, Proc. Int. Trib. Conf. Yokohama (1995) 415–420] and embedding or sintering of wear particles.