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:
Feb. 01, 2005
Filed:
Dec. 21, 2001
Kouji Funaki, Gifu, JP;
Katsura Matsubara, Aichi, JP;
Hiroki Watanabe, Gifu, JP;
Masaya Ito, Aichi, JP;
Kouji Funaki, Gifu, JP;
Katsura Matsubara, Aichi, JP;
Hiroki Watanabe, Gifu, JP;
Masaya Ito, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A silicon nitride sintered material containing a silicon nitride component and silicon carbide having an average particle size of 1 μm or less in an amount of at least 1 mass % and less than 4 mass %, based on 100 mass % of the silicon nitride component. The carbide is dispersed in the silicon nitride component, and the silicon nitride sintered material has a thermal expansion coefficient of at least 3.7 ppm/° C. between room temperature and 1,000° C. The silicon nitride component contains a rare earth element in an amount of 15-25 mass % as reduced to a certain oxide thereof and Cr in an amount of 5-10 mass % as reduced to a certain oxide thereof, and a crystalline phase is present in intergrain regions of the sintered material.