| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface coating cutting tool with a hard coating layer that exhibits a superior chipping resistance in heavy intermittent cutting.SOLUTION: A surface coating cutting tool has a Ti compound layer as a lower layer and a Ti-containing AlOlayer as an upper layer, coated and formed on the surface of a tool substrate. The Ti-containing AlOlayer of the upper layer comprises Ti-containingα-AlOcolumnar crystal grains having a lengthwise shape in the layer thickness direction, and also having anαtype crystal structure oriented in (10-14) faces, and Ti-containingκ-AlOcrystal grains having aκtype crystal structure. The Ti-containingα-AlOcolumnar crystal grains come into contact with recesses on a lower layer surface at the lower end. Alternatively, the Ti-containingκ-AlOcrystal grains come into contact with the surface other than the recesses on the lower layer surface at the lower end, and the Ti-containingκ-AlOcrystal grains are formed in the crystal grain gap in which the Ti-containingα-AlOcolumnar crystal grains are not adjacent with each other directly above the lower layer surface. |
