CBN sintered body cutting tool with excellent toughness

Abstract

An object of the present invention is to provide a cBN sintered body cutting tool with excellent toughness. While being used for interrupted cutting of high-hardness steel even if in the situation requiring high-load cutting conditions, the cutting tool provided by the invention is prevented from proneness to the cracks and defects of the blade and has excellent cutting performance which can be maintained for a long term. The cBN sintered body cutting tool comprises a sintered body including cubic boron nitride and a binder phase as a tool substrate, wherein a binder phase structure is existed in the area within 100nm from the grain boundary of the cubic boron nitride towards the binder phase, and is composed of one or more than two selected from the group of nitrides, carbides, carbon nitrides and borides of Ti, nitrides, borides and oxides of Al, and solid solution of more than two of them, and inevitable impurities, and has fine structures with an average volume diameter MV of 10-80 nm. Thus, the object of the present invention is achieved.

Description

technical field [0001] The invention relates to a cBN sintered body cutting tool which takes cubic boron nitride (hereinafter referred to as cBN) as the main component and sinters it under ultra-high pressure and high temperature. A cBN sintered cutting tool that can suppress the occurrence of chipping or chipping during interrupted cutting of high-hardness steel made of hardened materials such as steel, and can maintain excellent cutting performance over a long period of use. Background technique [0002] Conventionally, cBN sintered body cutting tools using a cBN sintered body as a tool base are known as high-hardness steel cutting tools, and various proposals have been made for the purpose of improving tool life in interrupted cutting. [0003] For example, as shown in Patent Document 1, cBN is contained at 25 to 47% by volume, and carbonitrides and borides of Ti are contained at a total of 40 to 70% by volume. The volume ratio of carbon and nitrogen in the carbonitrides ...

AI Technical Summary

Problems solved by technology

[0007] However, when cutting high-hardness steel with conventional cutting tools, there is no particular obstacle when cutting under normal conditions, but when interrupted cutting requires higher load cutting conditions, the toughness is insufficient. However, chipping or chipping of the tool tip is prone to occur, and there is a problem that sufficient cutting performance cannot be maintained over a long period of use.

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