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:
Jun. 04, 1985
Filed:
Aug. 08, 1983
Agency of Industrial Science & Technology, Tokyo, JP;
Abstract
Processes for the production of a silicon nitride sintered body are disclosed. One process comprises molding a mixed powder of 100 parts by weight of metallic silicon with a maximum particle size of 20 .mu.m or less and 0.2 to 2 parts by weight (calculated as chromium oxide) of a chromium component and, thereafter, reaction sintering the mold in a nitrogen gas or in a non-oxidizing atmosphere containing nitrogen gas at a temperature of 1,300.degree. to 1,500.degree. C. This invention provides further process which comprises molding a mixed powder of 100 parts by weight of metallic silicon with a maximum particle size of 20 .mu.m or less, 0.2 to 1 part by weight (calculated as chromium oxide) of a chromium component, and further 10 to 20 parts by weight of an oxide component of one or more of the oxides of yttrium, lanthanum, cerium, gadolinium, and erbium, reaction sintering the above-prepared mold, and thereafter, hot pressing the reaction sintered body. This silicon nitride hot pressed body is superior in oxidation resistance, and moreover is of high density and has high mechanical strength. Thus it is suitable for use as, e.g., gas turbine parts of diesel engine parts.