| 摘要 |
PURPOSE: A ceramic cutting tool that is cost-effective and capable of securing stable cutting performance for a long time even under a cutting condition wherein a high load is thermally and mechanically applied is provided. CONSTITUTION: The ceramic base(4) of a tool body(1) is made of a composite ceramic in which a hard phase having at least either one of a carbide, a nitride or a boride of a hard phase forming metal element M, or a solid solution of two or more kinds of those carbide, nitride and boride as a main ingredient, when one or two or more kinds of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Si are used as the hard phase forming metal element M, is dispersed in an alumina group matrix phase. The surface of the ceramic base(4) is covered with a coating layer(1f) having a titanium carbonitride or a titanium nitride as a main ingredient. The average size of a crystal grain observed on the surface of the coating layer(1f) is 0.1-0.5μm, and its average thickness is 0.5-2μm. Such coating layer(1f) is formed in a low and medium temperature range having a forming temperature of 750-900 deg.C by the CVD method. |
