摘要 |
A process for producing a heat-resistant ceramic sintered body, which comprises preparing polycarbosilane partly containing siloxane bonds by adding 0.01 to 15% by weight of polyborosiloxane containing phenyl groups in at least a part of the side chains of Si and having a skeletal structure composed of B, Si and O to a polysilane having the structure <IMAGE> wherein n is at least 3, and R1 and R2, independently from each other, represent methyl, ethyl, phenyl or hydrogen, and heating the polymer mixture in an atmosphere inert to the reaction thereby polymerizing it; mixing said polycarbosilane with a ceramic powder composed of at least one member selected from the group consisting of oxides, carbides, nitrides, borides and silicides; shaping the resulting mixture; and simultaneously with, or after, the shaping of the mixture, sintering the mixture at a temperature of from 800 DEG C. to 2,000 DEG C. in vacuum or in an atmosphere composed of at least one gas selected from the group consisting of inert gases, carbon monoxide gas, carbon dioxide gas, hydrogen gas, nitrogen gas and hydrocarbon gases. |