| 摘要 |
PROBLEM TO BE SOLVED: To improve the defect resistance of a hard coating layer by including a specific wt.% of Co and/or Ni, and adjusting the hardness of each part of a thermet base, and the thickness of the hard coating layer of the surface after the sintering, within the specific ranges. SOLUTION: When a thermet base is sintered, a content of Co and/or Ni as a binder phase component, is adjusted to be 0.5-6.5 wt.%. The cooling atmosphere is 1-5 Torr nitrogen atmosphere in the sintering conditions. Whereby the thermet base after the sintering, has 1600-2000 Hv, and a cutting ridge part has the maximum hardness of 3000-3400 Hv. On the other hand, a surface hardened layer having 2200-2600 Hv of the maximum surface hardness, is formed on a flank and a cutting face. A hard coating layer of 1-20μm of average layer thickness, is deposited on a surface of a titanium carbon nitride thermet base by physical evaporation method or chemical evaporation method. Whereby the hard coating layer is provided with the high defect resistance.
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