Ngk Spark Plug Company, Limited

Agency of Industrial Science and Technology

Hokko Chemical Industry Co., Ltd.

Nihon Cement Co., Ltd.

Kozo Iizuka, Director-general of Agency of Industrial Science and

Mino Yogyo Co., Ltd.

Shuzo Kanzaki

Hideyo Tabata

Osami Abe

Masayoshi Ohashi

Yamagishi Chitake

Koichi Moori

Tooru Shimamori

Ohta Shigetoshi

Mitachi Senshu

A sintered silicon oxynitride composition comprises as an amount of starting material the combination of (a) a silicon component comprising silicon nitride(Si.sub.3 N.sub.4) and silicon oxide(SiO.sub.2) in a mol ratio of SiO.sub.2 /Si.sub.3 N.sub.4 being 0.7 to 1.2, and (b) at least one second component selected from an aluminum oxide, an aluminum nitride, a rare earth oxide, and a rare earth nitride, said second component being in an amount of from about 0.1 to 10 mol per 100 mol of said silicon component.

Sintered high density silicon oxnitride and method for making the same

An alumina silica sintered ceramic that is produced by the normal sintering method and which has bending strength of at least 300 MPa at room temperature and at least 400 MPa at an elevated temperature, for example, 1,300.degree. C. is disclosed. This sintered ceramic is produced by a process comprising the following steps: providing a chiefly amorphous starting powder that consists of 62-73 wt % Al.sub.2 O.sub.3 and correspondingly 38-27 wt % SiO.sub.2 ; calcining this starting powder to make a calcined product that is chiefly composed of a crystalline phase and which contains oxides of an alkali metal and an alkaline earth metal in a total amount of no more than 1,500 ppm; pressing the ground particles of the calcined product into a compact; and sintering the compact at 1,500.degree.-1,750.degree. C. and at atmospheric pressure.

Process for producing alumina silica sintered ceramics having improved

Growing community of inventors

Aichi, Japan

Shuzo Kanzaki