Diamond-based ultra-high-pressure-sintered material having excellent chipping resistance, cutting tool made therefrom, and method of manufacturing the cutting tool

摘要

A cutting tool blank formed of material having a composition comprising of 0.1 to 20 wt % of BaCO3 and/or MgCO3, and/or 0.05 to 10 wt % of CaMg(CO3)2 or CaCO3, the balance being preferably substantially diamond forming a matrix is heated and maintained at a temperature of 800 DEG to 1400 DEG C. in a vacuum to change, by chemical reaction, the above BaCO3 and/or MgCO3, and/or CaMg(CO3)2 or CaCO3 into 0.05 to 13% of BaO and/or MgO and/or 0.02 to 5% of CaO, and to form pores. In this manner, a cutting tool formed of a diamond-based ultra-high-temperature-sintered material having a structure in which BaO, MgO and/or CaO are distributed finely and uniformly in a diamond matrix is obtained.