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. 13, 1994
Filed:
Oct. 22, 1992
Hironori Yoshimura, Ibaraki, JP;
Tetsuya Tanaka, Ibaraki, JP;
Akira Osada, Ibaraki, JP;
Toshikatsu Sudo, Ibaraki, JP;
Mitsubishi Materials Corporation, Tokyo, JP;
Abstract
The present invention concerns a tungsten carbide base cutting tools formed on sintered hard alloy substrate material. Multiple hard coatings are deposited on the Co-enriched surface layers of the substrate material, and a maximum value of the Co concentration in a layer occurs within a distance of 50 .mu.m of the external surface of the substrate material, and this surface layer region is referred to as the denuded zone because the surface region is substantially free of carbides, carbonitrides and nitrides of Ti, Ta, and Nb containing W. The multilayer coating consists of a primary coating of TiCN, a secondary coating of Al.sub.2 O.sub.3 and the surface coating consisting of at least one of TiCN and TiN. The interface between the substrate material and the primary coating is provided with a first intermediate coating consisting of TiN. The interface between the primary coating and the secondary coating is provided with a second intermediate coating consisting of at least one layer of TiC, TiCO and TiCNO.