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. 25, 2004
Filed:
Mar. 07, 2001
Applicant:
Inventor:
Yuki Hatano, Aichi, JP;
Assignee:
NGK Spark Plug Co., Ltd., Aichi, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C04B 3/5117 ; C04B 3/556 ;
U.S. Cl.
CPC ...
C04B 3/5117 ; C04B 3/556 ;
Abstract
An alumina-based composite sintered material comprising alumina as a main ingredient and containing one or more carbonitridation products of groups IVa, Va and VIa of the periodic table and/or two or more carbonitridation products of solid solutions of groups IVa, Va and VIa of the periodic table. The content of nitrogen solid solute in the carbonitridation product increases from the interior to the surface of the sintered material, and the Vickers hardness at the surface of the sintered material is 19.5 GPa or more.