Mitsubishi Materials Corporation

Takuya Hayahi

Takatoshi Oshika

Toshiaki Ueda

Eiji Nakamura

Akira Osada

Hisashi Honma

Fumio Tsushima

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 &#x3b1; crystal structure which is an upper layer, including the highest peak in the inclination section within a range of 0-10.

Cutting tool

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 &#x3bc;m, and (b) the upper layer is an aluminum oxide layer having an &#x3b1;-type crystal structure when chemically deposited and has an average layer thickness in the range of 1 to 15 &#x3bc;m. In the case of the upper layer, the reformed &#x3b1;-AlOlayer shows distribution graphs of covalent lattice points of constituent atoms, which shows distribution ratios of individual &#x3a3;N+1 to total &#x3a3;N+1, having the highest peak at &#x3a3;3 and showing the distribution ratios of &#x3a3;3 to total &#x3a3;N+1 in the range of 60 to 80%.

Surface-coated cermet cutting tool with hard coating layer exhibiting excellent chipping resistance in high-speed intermittent cutting

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 &#x3bc;m, and (b) as the upper layer, a heat-transformed &#x3b1;-type Al oxide layer formed by carrying out a heat-transforming treatment in a state that titanium oxide particulates satisfying the composition formula: TiO, (where value Y is 1.2 to 1.9 in an atomic ratio to Ti when measured by Auger Electron Spectroscopy) and chemically deposited as a transformation starting material are dispersedly distributed on a surface of an Al oxide layer having a &#x3ba;-type or &#x3b8;-type crystal structure deposited by chemical vapor deposition and satisfying the composition formula: (AlZr)O(where value X is 0.003 to 0.05 in an atomic ratio when measured by an electron probe micro-analyzer (EPMA)) to thereby transform the crystal structure of the Al oxide layer having the &#x3ba;-type or &#x3b8;-type crystal structure into an &#x3b1;-type crystal structure, the heat-transformed &#x3b1;-type Al oxide layer having an average thickness of 1 to 15 &#x3bc;m.

Surface-coated cermet cutting tool with hard coating layer having excellent chipping resistance

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 &#x3b1; crystal structure which is an upper layer, including the highest peak in the inclination section within a range of 0&#x2013;10.

Growing community of inventors

Naka-gun, Japan

Takuya Hayahi