Abstract: A surface-coated cermet cutting tool is formed by depositing on a surface of a tool substrate a hard-coating layer composed of the following layers (a) and (b): (a) the lower layer is composed of one or more layers of TiC, TiN, TiCN, TiCO, and TiCNO and has a total average layer thickness in the range of 3 to 20 ?m, and (b) the upper layer is an aluminum oxide layer having an ?-type crystal structure when chemically deposited and has an average layer thickness in the range of 1 to 15 ?m. In the case of the upper layer, the reformed ?-Al2O3 layer shows distribution graphs of covalent lattice points of constituent atoms, which shows distribution ratios of individual ?N+1 to total ?N+1, having the highest peak at ?3 and showing the distribution ratios of ?3 to total ?N+1 in the range of 60 to 80%.

Abstract: There is provided a surface-coated cermet cutting tool with a hard-coating layer having excellent chipping resistance. The surface-coated cermet cutting tool is formed by coating, on a surface of a tool substrate made of WC-based cemented carbide or TiCN-based cermet, a hard-coating layer including the following upper and lower layers (a) and (b): (a) as the lower layer, a Ti compound layer having at least one or two of a TiC layer, a TiN layer, a TiCN layer, a TiCO layer and a TiCNO layer, all of which are deposited by chemical vapor deposition, the titanium compound layer having a total average thickness of 3 to 20 ?m, and (b) as the upper layer, a heat-transformed ?-type Al oxide layer formed by carrying out a heat-transforming treatment in a state that titanium oxide particulates satisfying the composition formula: TiOY, (where value Y is 1.2 to 1.

Abstract: The present invention provides a cutting tool in which the hard coating layer demonstrates superior chipping resistance. The cutting tool has a tool base composed with tungsten carbide-based cemented carbide or titanium carbonitride-based Cermet, and a hard coating layer provided on the surface thereof; wherein the hard coating layer includes: (a) a Ti compound and/or Zr compound layer, which is a lower layer, comprising one or more layers of a TiC layer, TiN layer, TiCN layer, TiCO layer, TiCNO layer, ZrC layer, ZrN layer, ZrCN layer, ZrCO layer, ZrCNO layer and (b) an aluminum oxide layer having an ? crystal structure which is an upper layer, including the highest peak in the inclination section within a range of 0–10.

Abstract: A surface-coated cermet cutting tool is formed by depositing on a surface of a tool substrate a hard-coating layer composed of the following layers (a) and (b): (a) the lower layer is composed of one or more layers of TiC, TiN, TiCN, TiCO, and TiCNO and has a total average layer thickness in the range of 3 to 20 ?m, and (b) the upper layer is an aluminum oxide layer having an ?-type crystal structure when chemically deposited and has an average layer thickness in the range of 1 to 15 ?m. In the case of the upper layer, the reformed ?-Al2O3 layer shows distribution graphs of covalent lattice points of constituent atoms, which shows distribution ratios of individual ?N+1 to total ?N+1, having the highest peak at ?3 and showing the distribution ratios of ?3 to total ?N+1 in the range of 60 to 80%.

Abstract: There is provided a surface-coated cermet cutting tool with a hard-coating layer having excellent chipping resistance. The surface-coated cermet cutting tool is formed by coating, on a surface of a tool substrate made of WC-based cemented carbide or TiCN-based cermet, a hard-coating layer including the following upper and lower layers (a) and (b): (a) as the lower layer, a Ti compound layer having at least one or two of a TiC layer, a TiN layer, a TiCN layer, a TICO layer and a TICNO layer, all of which are deposited by chemical vapor deposition, the titanium compound layer having a total average thickness of 3 to 20 ?m, and (b) as the upper layer, a heat-transformed ?-type Al oxide layer formed by carrying out a heat-transforming treatment in a state that titanium oxide particulates satisfying the composition formula: TiOY, (where value Y is 1.2 to 1.

Abstract: The present invention provides a cutting tool in which the hard coating layer demonstrates superior chipping resistance. The cutting tool has a tool base composed with tungsten carbide-based cemented carbide or titanium carbonitride-based Cermet, and a hard coating layer provided on the surface thereof; wherein the hard coating layer includes: (a) a Ti compound and/or Zr compound layer, which is a lower layer, comprising one or more layers of a TiC layer, TiN layer, TiCN layer, TiCO layer, TiCNO layer, ZrC layer, ZrN layer, ZrCN layer, ZrCO layer, ZrCNO layer and (b) an aluminum oxide layer having an &agr; crystal structure which is an upper layer, including the highest peak in the inclination section within a range of 0-10.

Abstract: The present invention provides a cutting tool in which the hard coating layer demonstrates superior chipping resistance. The cutting tool has a tool base composed with tungsten carbide-based cemented carbide or titanium carbonitride-based Cermet, and a hard coating layer provided on the surface thereof; wherein the hard coating layer includes: (a) a Ti compound and/or Zr compound layer, which is a lower layer, comprising one or more layers of a TiC layer, TiN layer, TiCN layer, TiCO layer, TiCNO layer, ZrC layer, ZrN layer, ZrCN layer, ZrCO layer, ZrCNO layer and (b) an aluminum oxide layer having an ? crystal structure which is an upper layer, including the highest peak in the inclination section within a range of 0-10.