| 摘要 |
<p>A cutting tool 1 is a throwaway tip configured such that a hard coating is formed on the surface of a substrate formed of, for example, a hard material of cemented carbide (WC-Co-type cemented carbide) equivalent to JIS K10 and polished into the shape of ISO SPGN120312. Specifically, the cutting tool 1 is a plate-shaped positive tip whose rake face (the main surface side), which is the upper face in Fig. 1, is wider than the opposite face. The substrate surface is coated with a hard coating having a thickness in the range of from 1 mu m to 5 mu m, formed of a TiAIN material, and having a Ti/Al ratio of 1. Particularly, coarse grains present in the hard coating of this cutting tool and having a size not less than coating thickness occupy an area percentage not greater than 5% by area; and the hard coating has a surface roughness Ra of not greater than 0.1 mu m and a surface roughness Rz of not greater than 1 mu m. <IMAGE></p> |
