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:
May. 20, 1997
Filed:
Feb. 07, 1996
Harutoshi Ukegawa, Itami, JP;
Matsuo Higuchi, Itami, JP;
Abstract
A sintered silicon nitride-based body comprising 20% or less by weight of a grain boundary phase and the balance being a major phase of grains of silicon nitride and/or sialon, wherein the major phase contains a grain phase of a .beta.-Si.sub.3 N.sub.4 phase and/or a .beta.'-sialon phase, and a quantitative ratio of the grain phase of the .beta.-Si.sub.3 N.sub.4 phase and/or the .beta.'-sialon phase is in a range of 0.5 to 1.0 relative to the major phase; the grain boundary phase contains Re.sub.2 Si.sub.2 O.sub.7 (wherein Re represents a rare-earth element other than Er and Yb) as a first crystal component and at least one of ReSiNO.sub.2, Re.sub.3 Al.sub.5 O.sub.12, ReAlO.sub.3, and Si.sub.3 N.sub.4.Y.sub.2 O.sub.3 as a second crystal component; and a quantitative ratio of the first and second crystal components in the grain boundary phase to the grain phase of .beta.-Si.sub.3 N.sub.4 phase and/or the .beta.'-sialon phase ranges from 0.03 to 1.6. The sintered body is produced by mixing a specific sintering aid and silicon nitride-based powder, sintering the mixture and heat treating the sintered body for nucleation and crystal growth within the temperature range of from 1050.degree. to 1550.degree. C.