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This paper presents a study of the inverse heat conduction problem for high speed machining. A finite element method with an inverse scheme and an experimental measurement using infrared (IR) pyrometer with fiber optic are applied to predict the tool-chip interface temperature and the total heat dissipating to both tungsten carbide and ceramic inserts. A one-dimensional ellipsoidal mapping model of the cutting temperature distribution is adopted here and the average transient cutting temperature is calculated by the inverse finite element method with measured surface temperatures adjacent to the tool edge. Also the analysis of the errors coming from the sensor location and mapping model is studied. The results show the estimated cutting temperature is well convergent and agrees to other previous investigations. It is found that the thermal conductivity of the tool material has significant effect on the heat dissipation but little effect on the tool-chip interface temperature in high speed machining.

An infrared (IR) pyrometer system with an optical fibre was developed for measuring the temperature of a cutting tool during turning. The temperature reading of the pyrometer system was compared with the micrographs of the tool steels under welding conditions similar to those of cutting. It can be seen that the temperature of the tool measured by the IR pyrometer with an optical fibre is more accurate than that obtained by other on-line methods such as the conventional thermocouple technique. A one-dimensional ellipsoidal mapping system based on a model mapping of the temperature contours in the cutting tool was adopted in this study. It was used as an extrapolation scheme to predict the tool-chip temperature from the surface temperature measured near the cutting edge. There is a good agreement between the calculations and the metallurgical evidence for ceramic and carbide tools at cutting speeds up to 600 m min −1 .

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