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:
Feb. 18, 1997
Filed:
May. 01, 1995
Hideki Kato, Ichinomiya, JP;
Junichiro Suzuki, Gifu-ken, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
Si.sub.3 N.sub.4 based ceramics are prepared by molding, calcining and sintering a powder mixture of columnar-shaped Si.sub.3 N.sub.4 particles having a particular size, a minor quantity of sintering aids and equiaxed Si.sub.3 N.sub.4 particles. The ceramics have a structure containing a specific quantity of coarse columnar grains grown from the coarse columnar-shaped particles as seed crystals, and superior in wear resistance, resistance to chipping and thermal resistance, and useful as wear resistant components or cutting tools. The ceramics can be produced without recourse to hot press sintering by normal sintering or sintering under a gas pressure, or further by applying HIP.