| 摘要 |
PROBLEM TO BE SOLVED: To provide a cutting tool, made of a sintered diamond, excellent in fracture resistance and capable of manifesting excellent cutting performances for a long period. SOLUTION: This cutting tool is composed of a sintered diamond having a composition comprising 80-90 vol.% diamond coarse grains having 10-50 μm grain diameter and 20-30 μm average grain diameter and 50-10 vol.% diamond fine grains having <=7 μm grain diameter and 2-4 μm average grain diameter, a sintering assistant component comprising one or more of carbonates and oxides of Mg, Ca, Sr and Ba and inevitable impurities and further having a structure in which the diamond coarse grains are mutually adjacently bonded; the sintering assistant component is present among the diamond coarse grains and the diamond fine grains are dispersed and distributed in the sintering assistant component. |
