Patent ID: 6287682
Filing Date: 2001-09-11
Classification: B23B,C23C,Y10T

Abstract:
A diamond coated cutting tool for chip forming machining of materials comprising:a tungsten carbide based cemented carbide substrate having tungsten carbide grains bonded together by a metallic binder selected from the group consisting of cobalt and cobalt alloys;wherein said substrate has a substrate surface with relatively large tungsten carbide grains thereat, as compared to said tungsten carbide grains in the interior regions of the substrate, to provide an irregular surface on said substrate;a diamond coating deposited upon, and having a strong adherence to, said irregular substrate surface;wherein said diamond coating adheres to the irregular substrate surface with an average adhesion strength of greater than 45 kilograms in Rockwell A indentation tests;wherein said substrate has a flank surface and a rake surface and a cutting edge formed at the juncture of said flank and rake surfaces;wherein said diamond coating is adherently bonded to said rake surface and said flank surface;wherein said tungsten carbide based cemented carbide having a composition consisting essentially of tungsten, carbon, cobalt and less than 1 w/o total of Ti, Hf, Zr, Ta, Nb, V, Mo and Cr, and wherein the Ta content is less than or equal to 0.4 w/o, the Ti content is less than or equal to 0.1 w/o and the Nb content is less than or equal to 0.1 w/o; andwherein said substrate is characterized by an absence of interconnected porosity in the substrate region adjacent to said irregular substrate surface.