National Institute for Materials Science

Nof Corporation

National Institute for Research in Inorganic Materials

National Institute for Materials

Toshimori Sekine

Hongliang He

Takamichi Kobayashi

Mamoru Mitomo

Katsuhiko Takahashi

Kenji Ito

Koji Kimoto

A method for preparing a high-pressure phase cubic spinel-type silicon nitride includes housing a molding containing low-pressure phase silicon nitride powder and a metal powder in a cylindrical container, arranging an explosive in the cylindrical container so as to surround the molding, and exploding the explosive to compress the molding. An X-ray diffraction pattern of the high-pressure phase cubic spinel-type silicon nitride produced according to the method of the present invention shows a maximum peak having a full width at half maximum of 0.65 degrees or less. TG-DTA analysis of the cubic spinel-type silicon nitride shows a weight change starting temperature of 700 to 1100&#xb0; C.

High-pressure phase silicon nitride having a cubic spinel structure and the manufacturing method

A large amount of spinel type silicon nitride powders of a high-pressure phase is produced by mixing raw powders having a particle size of 10 &#x3bc;m or less of &#x3b1;-, &#x3b2;- or amorphous silicon nitride, each of which is a low pressure phase, with non-nitrified metal powders at a ratio of 50 weight % or more, preferably copper powders with a particle size of 100 &#x3bc;m or less, forming a compact with porosity of 50% or less and 10% or more, preferably around 30%, by pressing mixture powders obtained, and subjecting the compact to shock wave compression treatment at a pressure of 20 GPa or more, preferably around 60 GPa.

Process for synthesizing spinel type silicon nitride powders

A high pressure phase spinel type sialon represented by the chemical formula Si Al O N (0<x&lE;4.2), and a high pressure phase spinel type silicon oxynitride represented by the chemical formula Si O N (&boxH;Si N .xSiO , 0<x<1). Methods for their production by instantaneous pressing by means of an impulse wave.

Spinel type sialon, spinel type silicon oxynitride and methods for producing their powders

Growing community of inventors

Ibaraki, Japan

Toshimori Sekine