Measurement of Tool-Workpiece Interface Temperature by Two-Color Pyrometer

Abstract

Temperature of interface between a cutting tool and a workpiece is measured using two-color pyrometer with a fused fiber coupler. A conical tool is used as the cutting tool which is made of translucent alumina sintered under HIP, and 0.55% carbon steel is used as a workpiece. The infrared rays radiated from the interface and transmitted through the conical tool are accepted by a fused fiber coupler and led to two infrared detectors of different spectral sensitivity. Temperature is obtained by calculating the ratio of the output voltage from these two detectors. The results obtained are as follows. The temperature increases very rapidly and reaches 1000°C at about 40 μs after the beginning of cutting. The rate of increase of temperature is very great : about 108 °C/s at the cutting speed of 1 500 m/min. The temperature increases with the increase of cutting speed, but at a speed faster than 1000 m/min its influence is small. The temperature shows a tendency to saturate about 1300-1400°C as the cutting speed increases. © 1995, The Japan Society for Precision Engineering. All rights reserved.