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:
Dec. 14, 1999
Filed:
Aug. 31, 1998
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A silicon nitride sintered body prepared through a nitriding reaction of Si, consists of crystal grains mainly composed of silicon nitride and/or SIALON and a grain boundary phase. The grain boundary phase includes a first component including at least one element selected from a group of Na, K, Mg, Ca and Sr and a second component including at least one element selected from a group of Y and lanthanoid series elements. The molar ratio of the first component to the second component is in the range of 1:1 to 6:1 in terms of oxides. The mean breadth and the mean length of the crystal grains are not more than 0.1 .mu.m and not more than 3 .mu.m respectively, and the standard deviation of the mean length in the sintered body is within 1.5 .mu.m. Especially, the mean breadth of the crystal grains is at least 0.4 .mu.m and not more than 0.9 .mu.m.