| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface coated cutting tool having a hard coating layer showing excellent chipping resistance in heavy cutting of a difficult-to-cut material. SOLUTION: In the surface coated cutting tool, the following hard coating layer is forme on the surface of a tool base. The hard coating layer is formed of; a lower layer (a); and an upper layer (b). The lower layer (a) is formed of a composite nitride layer of Cr and Al or a composite nitride layer of Cr, Al, and M (wherein, M is one type or two types or more of elements selected among the elements Si, B, and Y of the groups IVa, Va, and VIa in the periodic table excluding Cr). The upper layer (b) has an oxygen density distribution structure where an oxygen containing rate is increased toward the layer thickness direction, and is formed of a composition inclined type vanadium oxynitride layer where oxygen is not substantially included on the far lowest surface and nitrogen is not substantially included on the uppermost surface. COPYRIGHT: (C)2008,JPO&INPIT
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