COMBINED SINTERED COMPACT AND ITS PRODUCTION

摘要

PURPOSE:To obtain a combined sintered compact having high strength without deteriorating fracture toughness by constituting a sintered compact so that the blending proportion of two kinds of ceramics is different between the inner part and the surface part of the sintered compact by using two kinds of non- oxide ceramics dissimilar in the coefficient of thermal expansion. CONSTITUTION:The above sintered compact is a sintered compact which consists of two kinds of non-oxide ceramics and in which the blending proportion of the non-oxide ceramics having higher coefficient of thermal expansion is regulated so that it is higher in the inner part of this sintered compact than in the surface part of this sintered compact. As the combination of the above- mentioned two kinds of non-oxide ceramics, e.g. a combination of silicon carbide and at least either of the boride and the carbide of the group VIa-VIa elements of the periodic table and a combination of alpha'-silicon nitride and beta'-silicon nitride are cited.