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. 07, 2002
Filed:
Jun. 22, 2000
Applicant:
Inventors:
Hiroshi Yamamoto, Ichinomiya, JP;
Satoshi Iio, Kagamigahara, JP;
Assignee:
NGK Spark Plug Co., Ltd, Aichi, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C04B 3/510 ;
U.S. Cl.
CPC ...
C04B 3/510 ;
Abstract
Alumina-based ceramics are thermally stable because of their high melting point and excellent materials in wear resistant properties and chemical stability. However, they contradictly have such a problem that fracture toughness is low, and its improvement is desired. The present invention provides such sintered alumina-based ceramics and their production process that have rendered to grow alumina grains anisotropically and fracture simultaneously attain high flexural strength and fracture toughness by sintering the formed mixture comprising Al O , 0.05-2.5 mol % of VA metal oxide and 0.01-4 mol % SiO , relative to Al O , respectively.