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:
Jul. 06, 1999
Filed:
Aug. 27, 1998
Applicant:
Inventors:
Assignee:
Kyocera Corporation, Kyoto, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C04B / ;
U.S. Cl.
CPC ...
501 972 ;
Abstract
A silicon nitride sintered body containing a .beta.-silicon nitride crystal phase and further containing at least a rare earth element component and an aluminium component in a grain boundary phase, wherein the intensity ratio (X2/X1) of the Si peak X.sub.2 at 521 cm.sup.-1 to the Si.sub.3 N.sub.4 peak X.sub.1 at 206 cm.sup.-1, as detected by a Raman spectrochemical analysis method, is 0.2 to 3. A very minor amount of Si (elemental silicon), as detected by the Raman spectrochemical analysis method, is precipitated in the sintered body, and by this precipitation of Si, strength and toughness are markedly increased.