| 摘要 |
PROBLEM TO BE SOLVED: To restrain the advancement of abrasion by applying the constitution that a hard layer containing diamond grains as a main component is formed on the surface of a tip body made of cemented carbide, and another hard layer mainly composed of CBN grains is formed in the former hard layer. SOLUTION: The first hard layer 7 containing diamond grains 6 as a main component is formed on the cutting face of a tip body 1, while the second hard layer 9 containing CBN grains 8 as a main component is formed on the first hard layer 7. In this case, the size of each diamond grain 6 contained in the first hard layer 7 is between 300μm and 20μm. According to this construction, the abrasion of the second hard layer 9 containing the CBN grains 8 is restrained at the time of cutting a nonferrous metal material such as aluminum alloy as a hard-to-cut material and the abrasion of the diamond grains 6 in the first hard layer 7 due to reaction with a ferrous metal part is prevented. |
