Mitsubishi Materials Corporation

Naoyuki Iwasaki

Akira Osada

Sho Tatsuoka

Kenji Yamaguchi

Makoto Igarashi

A surface-coated cutting tool includes a body and a hard coating layer coating the cutting tool body. In the surface-coated cutting tool, the (TiAl)(CN) layer with a cubic crystal structure (X and Y are atomic ratio, and satisfy 0.60&#x2266;X&#x2266;0.90 and 0.0005&#x2266;Y&#x2266;0.005, respectively) is vapor-deposited on the body by a chemical vapor deposition method. The Al content Xis 0.55&#x2266;X&#x2266;0.70, and the grain size Dis 0.1 &#x3bc;m or less in the (TiAl)(CN) layer near the interface between the body and the complex carbonitride layer. The Al content X0.80&#x2266;X&#x2266;0.95 and the average grain size Dis 0.5 &#x3bc;m to 2 &#x3bc;m in the (TiAl)(CN) layer near the outer surface side. Furthermore, the Al content ratio and the grain size in the (TiAl)(CN) layer gradually increase to the outer surface side.

Surface-coated cutting tool having therein hard coating layer capable of exhibiting excellent chipping resistance during high-speed intermittent cutting work

A coated tool with a hard coating layer, which has an excellent hardness and heat insulating effect; and exhibits an excellent chipping resistance and an excellent fracturing resistance for a long-term usage, is provided. The hard coating layer included in the coated tool has a chemically vapor deposited alternate laminated structure, which is made of: a region A layer and a region B layer, each of which is expressed by the composition formula of (TiAl)(CN); and has the average total layer thickness of 1-10 &#x3bc;m. In the region A layer, relationships, 0.70&#x2266;x&#x2266;0.80 and 0.0005&#x2266;y&#x2266;0.005, are satisfied; the average grain width W is 0.1 &#x3bc;m or less; and the average grain length L is 0.1 &#x3bc;m or less. In the region B layer, relationships, 0.85&#x2266;x&#x2266;0.95 and 0.0005&#x2266;y&#x2266;0.005, are satisfied; the average grain width W is 0.1-2.0 &#x3bc;m; and the average grain length L is 0.5-5.0 &#x3bc;m.

Growing community of inventors

Naka, Japan

Naoyuki Iwasaki