Mitsubishi Materials Corporation

Hiroki Nakamura

Kousuke Yanagisawa

Hisashi Honma

Takuya Ishigaki

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.

Growing community of inventors

Joso, Japan

Hiroki Nakamura