The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 24, 1978
Filed:
Jan. 27, 1977
Masaaki Mori, Hadano, JP;
Norihira Takai, Yamato, JP;
Toshiba Ceramics Co., Ltd., Tokyo, JP;
Abstract
A process for preparing silicon nitride powder having a high .alpha.-phase content which comprises the steps of (a) providing a blended powder material composed of silica powder and amorphous carbon powder having an oil absorption of not less than 100 ml/100g, the weight ratio of the carbon powder to the silica powder being not less than 0.5, and then (b) nitriding and burning the blended powder material by heating in at a temperature of from 1300.degree. to 1700.degree. C while feeding a nitrogen-containing, non-oxidizing gas. The product obtained by this process is suitable as a raw material for the manufacture of high-density and high-strength sintered articles of silicon nitride.