| 摘要 |
PURPOSE: A cutting tool capable of extending life cycle of the tool by improving wear resistance and toughness at the same time by optimizing TiBCxNy (x+y≒1, B: 0.01 to 1 vol.%) coating conditions. CONSTITUTION: In a hard metal surface coated cutting tool in which a hard coating layer comprising a compound layer formed from one or more layers selected from titanium carbide layer, titanium carbonitride layer, titanium oxide layer, titanium nitrate layer and titanium carbonitrite layer having average thickness of 0.1 to 5 μm and granular crystal structure, TiBCN layer having columnar crystal structure and granular crystal structure of 2 to 15 μm and aluminum oxide layer having average thickness of 0.5 to 8 μm and granular crystal structure is chemically or physically deposited to the total average thickness layer of 3 to 25 μm on the surface of tungsten carbide based hard metal base metal, the hard metal surface coated cutting tool is characterized in that the TiBCN layer has film thickness directional concentration gradients of B, C and N in which Y is 0.05 to 0.35, B is 0.08 to 1 vol.% in the upper surface part, and Y is 0.65 to 0.95, B is 0 to 0.08 vol.% in the lower surface part as atomic ratio, and the TiBCN layer has concentration gradients in which concentration of B, C and N is not changed in step or changed in step when representing the TiBCN layer having dendrite structure and granular crystal structure composing the hard coating layer in the following composition formula of the upper and lower surface parts: TiBCxNy (x+y≒1, B: 0.01 to 1 vol.%).
|
