US 5,177,038 A · Silicon nitride sintered bodies

Abstract

Silicon nitride sintered bodies are disclosed which contain silicon carbide therein and in which intergranular phases between silicon nitride particles are substantially crystallized. Further, a manufacturing method of the sintered bodies is disclosed, in which a silicon carbide powdery raw material is used as an additive when preparing raw powders and the intergranular phases are crystallized during a temperature descending stage following a firing. Silicon carbide effectively promotes densification of the structure of the sintered body and crystallization of the intergranular phases, thereby making it possible to provide the sintered bodies having intergranular phases with little glass phases uncrystallized and excellent high-temperature strengths.

Claims8

Dependent claims

A silicon nitride sintered body consisting essentially of:

silicon nitride;
oxides of rare earth elements in an amount of 2.7-10 mol %, said oxides including at least an oxide of Yb;
and
silicon carbide in an amount of 0.1-11 wt % relative to an amount of a formulated powder consisting of said silicon nitride and said oxides of rare earth elements;
wherein intergranular phases between silicon nitride particles contained in said silicon nitride sintered body are substantially crystalline.

2 more elements

Dependencies are inferred from the claim text.

Silicon nitride sintered bodies

Life of this patent

Silicon nitride sintered bodies

Life of this patent

Abstract

Claims8