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:
Jun. 23, 1992
Filed:
Sep. 04, 1990
Sakae Katayama, Sagamihara, JP;
Masayuki Hashimura, Sagamihara, JP;
Hiroto Imamura, Kitakyushu, JP;
Tetsuo Sawashima, Neyagawa, JP;
Nippon Steel Corporation, Tokyo, JP;
Nippon Hardmetal Co., Ltd., Tokyo, JP;
Toho Kinzoku Co., Ltd., Osaka, JP;
Abstract
A cemented carbide tool of excellent wear resistance and fracture resistance includes a substrate of cemented carbide, and a ceramic coating layer by chemical vapor deposition. The thickness of the layer is in the range of between 2 .mu.m to 20 .mu.m, and the layer has cracks of such a depth that the cracks extend perpendicularly from a surface of the layer to the substrate. The cracks are formed in a network-like pattern to minutely divide the layer. The average value of the depths of the cracks in a direction perpendicular to the surface of the layer is not less than the thickness of the layer and not more than a value equal to the coating thickness plus 5 .mu.m. The average value of widths of the cracks is not more than 2 .mu.m. The average value of intervals between the cracks is not less than 10 .mu.m and not more than 100 .mu.m.