| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface coated cutting tool in which a hard coating layer exhibits superior chipping resistance and breakage resistance in high-speed intermittent cutting work.SOLUTION: A surface coated cutting tool has a hard coating layer consisting of a lower layer, a middle layer and an upper layer on a surface of a tool base body constituted of WC-based cemented carbide or TiCN-based cermet. In the hard coating layer, (a) the lower layer consists of one layer or two or more layers out of a Ti carbide layer, a nitride layer, a carbonitride layer, a carbonate layer, and a carbonitroxide layer, and is a Ti compound layer having a total average layer thickness of 3-20 μm; (b) the middle layer is an aluminium oxide layer including an α type crystalline structure having an average layer thickness of 0.5-5 μm; (c) the upper layer is an aluminium oxide layer having an average layer thickness of 1-25 μm in which amorphous aluminium oxide phases are present; and a crystalline orientation of the middle layer, an occupied ratio of tabularly grown aluminium oxide crystalline phases in the upper layer, and the like are regulated. |
