Temperature variation in the workpiece and in the cutting tool when dry milling Inconel 718

The cutting temperature is an important parameter controlling the tool life and the quality of machined surfaces; its determination is therefore a key objective when dry machining difficult-to-cut materials. It is well known that maximum temperature is obtained in the tool rake face at the vicinity of the cutting edge. A moderate level of cutting edge temperature and a low thermal shock reduce the tool wear phenomena, and a low temperature gradient in the machined sublayer reduces the risk of high tensile residual stresses. This paper deals with temperature and temperature gradient measurements during dry peripheral milling of Inconel 718. The thermocouple method was used to measure the temperature of the machined surface and in the subsurface layer. An original thermocouple was specially developed for measuring the machined surface temperature. The measurements were used to determine the temperature gradients and to reconstruct the thermal heating of the cutting edge at every tool revolution and for different cutting speed values.