Sliding member of high strength and high abrasion resistance

Claim 1

A sliding member of high strength and high abrasion resistance, preponderantly comprising elongated particles of β-phase silicon nitride and not more than 20% by weight, based on the total amount of said sliding member, of a matrix phase enveloping said silicon nitride particles, said particles having major diameters of not more than 60 μm and aspect ratios of not less than 5, said sliding member having a relative density of not less than 98%, and said sliding member consisting essentially of silicon nitride and effective amounts of an oxide of a rare earth element, aluminum oxide and a member selected from the group consisting of titanium oxide, zirconium oxide and magnesium oxide, said sliding member formed by mixing not more than 10% by weight of the oxide of a rare earth element, not more than 10% by weight of aluminum oxide, not more than 5% by weight of at least one member selected from the group consisting of titanium oxide, zirconium oxide and magnesium oxide, (excluding the case wherein both said oxide of rare earth and aluminum oxide both account for 0% by weight) with silicon nitride powder in proportions such that the ratio of said oxide of rare earth element to aluminum oxide will fall in the range of 0.5 to 10, and sintering the resultant mixture.