| 摘要 |
PURPOSE: To avoid or alleviate problems of conventional coatings such as decrease of crater wear resistance and grain boundary sliding and to provide a coating layer with controlled grain size and morphology right above the nanograined region, wherein grain size of MTCVD Ti(C,N) is reduced, and columnar grain structure is maintained to reduce grain boundary sliding at high temperature. CONSTITUTION: In a cutting tool inert which is formed of a cemented carbide, cermet or ceramic substrate, and at least a part of which is coated with a coating having the total thickness of 10 to 40μm, preferably 15 to 25μm and consisting of one or more refractory layers which are MTCVD(medium temperature chemical vapor deposition)-Ti(C,N) layers, and at least one layer of which has thickness of 3 to 30μm, preferably 5 to 20μm, the cutting tool inert is characterized in that the layer is constructed in a columnar grain structure which has a grain size of 30 to 300 nm, preferably 50 to 200 nm and a ratio(L/W) of length to width of not less than 3, preferably exceeding 5. |
