| 摘要 |
PURPOSE:To improve the wear resistance, oxidation resistance and fusion bond resistance of a cutting tool and thereby prolong the life thereof, by doubly coating the surface of the cutting tool with one of carbide, nitride and carbonitride of a solid solution of titanium and hafnium, and a TiC film. CONSTITUTION:A coating process for a cutting tool can be divided into two steps, i.e. a step of forming a film of a solid solution of a titanium compound and a hafnium compound on a super-hard alloy, and a step of forming a TiC film on the above-mentioned film. The formation of (Ti.Hf)C in the first step can be expressed by the reaction formulae as follows. Hf+2I2 HfI4-(1), Ti+2I2 TiI4-(2), 4HfI4+4TiI4+C4H10 4(Hf.Ti)C+10HI+11I2-(3). In the reaction formulae, (1), (2), the formation of TiI4 and HfI4 is carried out by introducing a predetermined amount of iodine vapor (I2) into a mixture of Ti and Hf in the form of a metal heated to a predetermined temperature, to carry out a reaction. Thus, a cutting tool having improved wear resistance, oxidation resistance and fusion bond resistance and a prolonged life can be obtained. |
