Abstract
The influence of cutting speed, and thermal properties of the work material and the tool material on the thermal partition coefficient is investigated theoretically and experimentally. The temperature at the top of a conical tool is measured immediately after micro chip forming using an infrared radiation pyrometer with an optical fiber. A carbon steel, a titanium, a molybdenum and a tungsten are used as work materials, and a silicon nitride Si3N4, a zirconia ZrO2 and a diamond are used as tool materials. The cutting temperature increases in proportion to the 1/2 power of cutting speed and saturates to the melting point of work material. The fraction of heat conducted into the cutting tool is independent on the cutting speed, and it becomes larger as the thermal conductivity of workpiece is smaller or that of tool material is larger. In the diamond tool which has the highest thermal conductivity, its thermal partition coefficient is the highest, but the tool tip temperature is the lowest.
