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:
Nov. 11, 1986
Filed:
Mar. 05, 1985
Michitaka Mizutani, Tsu, JP;
Kyocera Corporation, Kyoto, JP;
Abstract
In preparing a sintered silicon nitride body by hot isostatic pressing, a composition comprising Si.sub.3 N.sub.4 and a sintering aid is molded to form a green molded body, the surface of the green molded body is coated with a composition comprising Si.sub.3 N.sub.4 and a sintering aid and having a sintering temperature lower than that of the composition of the green molded body, the coated green molded body is preliminarily sintered so that only the coating layer is densified, and the preliminarily sintered molded body is subjected to hot isostatic pressing. The obtained sintered body has a surface compression stress, and by this surface compression stress, not only the strength at room temperature but also the strength at high temperatures is improved.