| 摘要 |
PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated cemented carbide excellent in chipping resistance and capable of prolonging the service life over a long period. SOLUTION: In this cutting tool made of surface coated cemented carbide, on the surface of a WC base cemented carbide substrate, a hard coating layer composed of a Ti compd. layer consisting of one or >= two kinds among a TiC layer, a TiN layer, a TiCN layer, a TiCO layer, a TiNO layer and a TiCNO layer and an Al2 O3 layer is chemically vapor-deposited and/or physically vapor-deposited by the average layer thickness of 3 to 20μm. In this case, a Ti2 O3 series two phase structural layer composed of two phases of a Ti2 O3 phase and a TiCO phase or a Ti2 O3 phase and a TiCNO phase, and in which the ratio of the TiCO phase or the TiCNO phase occupied in the total content with the content of the Ti2 O3 phase is regulated to 2 to 50 area % by structural measurement with an optical microscope is formed by the average layer thickness of 0.1 to 5μm by chemical vapor deposition or physical vapor deposition in such a manner that it is interposed between the Ti compd. layer and the Al2 O3 layer.
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