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:
Sep. 16, 1997
Filed:
May. 30, 1996
Masahiro Sato, Kokubu, JP;
Yukiyasu Aoyama, Sendai, JP;
Nobuoki Takagi, Sendai, JP;
Shoji Kohsaka, Kokubu, JP;
Kyocera Corporation, Kyoto, JP;
Abstract
A cutting tool composed of silicon nitride comprising chiefly a .beta.-silicon nitride crystal phase and containing a grain boundary phase of rare earth elements, silicon, aluminum, oxygen and nitrogen, wherein the cutting surface is constituted by at least a fired surface or a surface formed by removing and polishing the fired surface by an amount of not larger than 10 .mu.m, and has in the mirror surface thereof a micro-Vicker's hardness which is higher than that of the interior thereof and is not smaller than 16 GPa. The cutting tool has a cutting surface that can be easily worked enabling the cost of working to be decreased, and has a highly hard layer that is suited for cutting cast iron and the like materials featuring increased durability and extended cutting life.