Radiational Thermometry of Diamond Tool Tip Temperature in Micro Cutting

Abstract

A diamond tool tip temperature in a micro cutting was measured by a two color pyrometer with an optical fiber. The use of the fiber facilitates the acceptance of infrared rays radiated from a very small cutting area. The independence of a two color pyrometer from a size of an object was experimentally confirmed. In the cutting experiment, a conical, single crystal diamond and a sintered aluminum were used as cutting tools, and a titanium and a tungsten carbide were used as workpieces. The tool has a small hole and the fiber was inserted into the hole. During the cutting, the fiber accepts the infrared rays radiated from the tool-chip interface and transmitted through the cutting tool. The diamond tool tip temperature in titanium cutting is 300°C when the depth of cut is 2μm and 600°C at 45μm. Compared with the cutting with aluminum tool, the diamond tool tip temperature is much lower than the aluminum tool tip temperature. In the cutting of tungsten carbide, the diamond tool tip temperature is over 1000°C when the depth of cut is 1mm. The tool is worn with cutting and the tool tip temperature increases with the tool wear.