Determination of emissivity and temperature of tool rake face when cutting AISI 4140

A method for measuring tool temperature in the tool/chip contact zone of the rake face of a tool during dry orthogonal cutting using thermography is presented. This method used a new calibration method that combined with a standard camera calibration allows to estimate surface emissivity. The effect of material deposition and tool oxidation on the emissivity is analyzed. These techniques effectively showed thermal field on the rake face when machining AISI 4140.