Mitsubishi Materials Corporation

Hisashi Honma

Kousuke Yanagisawa

Takuya Ishigaki

Hiroki Nakamura

Eiji Nakamura

Akira Osada

Takuya Hayahi

Provided is a surface-coated cutting tool including a complex carbonitride layer on the tool body, wherein a ratio of crystal grains having a NaCl type face-centered cubic structure is 80 area % or more, xand ysatisfy 0.60≤x≤0.90 and 0.000≤y≤0.050, respectively, a composition of the Ti—Al complex carbonitride layer being represented by (TiAl)(CN), the xbeing an average of x that is an Al content in a total content of Al and Ti, and the ybeing an average of y that is a C content in a total content of C and N, the crystal grains having the NaCl type face-centered cubic structure include crystal grains in which the x repeatedly increases and decreases, the crystal grains include 10 to 40 area % of crystal grains Ghaving an average distance of 40 to 160 nm and crystal grains Ghaving an average distance of 1 to 7 nm.

Surface-coated cutting tool

A surface-coated cutting tool includes a tool body and a hard coating layer, where one TiAlCN layer α () containing 70 area % or more of a wurtzite type hexagonal structure on a tool surface side (S) and one TiAlCN layer β () containing 70 area % or more of a NaCl type face-centered cubic structure on the tool body side (B), when a composition of the TiAlCN layer α () is represented by (TiAl)(CN) satisfying 0.70≤xα≤0.95 and 0.000≤yα≤0.010, when a composition of the TiAlCN layer β () is represented by (TiAl)(CN) satisfying 0.65≤xβ≤0.95 and 0.000≤yβ≤0.010, and when average layer thicknesses of the TiAlCN layer α () and the TiAlCN layer β () are defined as Lα and Lβ satisfying 0.5 μm≤Lα≤10.0 μm and 1.0 μm≤Lβ≤20.0 μm.

A surface coated cutting tool comprises a tool body. A TiAlCN layer having an average layer thickness of 2.0 to 20.0 μm and represented by (TiAl)(CN) is provided on the surface of the tool body and has an average content ratio xof Al and an average content ratio yof C that satisfy 0.60≤x≤0.95 and 0.00≤y≤0.05, an area ratio occupied by crystal grains having an NaCl-type face-centered cubic structure that satisfies 90 area % or more, and crystal grains satisfying 0.01 μm<d≤0.20 μm in 10 to 40 area %. An average maximum length in a direction parallel to the surface of the tool body in each region in which the crystal grains having d of 0.01 μm<d≤0.20 μm are adjacent and connected to each other in the upper layer side region is 5.0 μm or less.

Surface coated cutting tool having hard coating layer exhibiting excellent chipping resistance

A surface coated cermet cutting tool comprising a tool body and a hard coating layer formed on the surface of the tool body, wherein the hard coating layer has a lower layer of a titanium compound layer and an upper layer of property-modified &#x3b1; type AlOlayer that has a crystal grain boundary orientation determined using a field emission type scanning electron microscope and an electron back-scattered diffraction pattern imaging device such that crystal grain boundary units of not less than 45% of all the grain boundaries show intersection angles of 15&#xb0; or less between normals of (0001) planes and between normals of {10-10} planes, where a crystal grain boundary unit is a crystal grain boundary of adjacent pair of crystal grains.

[object Object]

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%.

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Naka, Japan

Hisashi Honma