2017 年 83 巻 856 号 p. 17-00344
In high speed turning, six kinds of materials, namely, Ti-6Al-4V, Inconel718, SUS304, S50C, Copper and Aluminum are machined with a ceramic cutting tool in order to investigate the influence of the cutting speed on the temperature of the cutting tool experimentally. The cutting temperature is measured by the two-color pyrometer with an optical fiber which is developed by the author. In cutting of Ti-6Al-4V and Inconel718 with Al2O3 ceramic tool, the cutting temperature increases with the increase of cutting speed and approaches to the melting points of the workpiece materials. The thermal conductivities of these difficult-to-cut materials are small, and Al2O3 ceramic has a small thermal conductivity and maintains a high strength even at the temperature of about 1000°C. In the cases of Copper and Aluminum, their thermal conductivities are much larger than those of Ti-6Al-4V and Inconel718, so that the cutting temperature increases so slowly with the increase of cutting speed that it is difficult to approach to the melting points of the workpiece materials.