Patent ID: 9186728
Filing Date: 2015-11-17
Classification: B23B,C22C,Y10T

Abstract:
1. A cutting tool comprising a hard sintered body in at least a cutting edge, said cutting tool having a rake face and a flank face, said rake face having a chip breaker in a protruded or uneven shape, said hard sintered body having said rake face and said flank face, said hard sintered body containing at least 20% by volume of cubic boron nitride, a region of not more than 20 μm in a depth direction from a surface of said hard sintered body on the rake face side including A-structures made of cubic boron nitride and B-structures made of at least one selected from the group consisting of hexagonal boron nitride, amorphous boron nitride, and boron oxide, and a volume ratio of said B-structures to a sum of said A-structures and said B-structures, B/(A+B), being not less than 5% by volume and not more than 90% by volume, and said B-structures are obtained by transforming said A-structures in the surface of said hard sintered body using any of electrical discharge machining, electron beam machining, laser machining, and plasma arc machining.