| 摘要 |
PROBLEM TO BE SOLVED: To provide a coated tool which has a hard coat layer excellent in hardness and toughness and exhibits chipping resistance and defect resistance over a long-term use.SOLUTION: A surface coated cutting tool includes: a tool base body and a hard coat layer disposed on the surface of the tool base body. Therein, the hard coat layer contains a composite nitride layer or a composite carbonitride layer represented by a compositional formula:(TiAl)(CN), an average content proportion of Al Xand an average content proportion of C Y(either of Xand Yis atomic ratio) are respectively 0.60≤X≤0.95 and 0≤Y≤0.005, the composite nitride layer or the composite carbonitride layer contains a crystal grain having a cubic crystal structure and compositions of Ti and Al are changed periodically in a normal direction on the surface of the tool base body in the crystal grain having the cubic crystal structure. |
