Thermal Influence Analysis of Coatings and Contact Resistance in Turning Cutting Tool using Comsol

Abstract In machining processes, cutting tools reach temperatures higher than 900ºC, thus deteriorating their mechanical properties. To reduce this problem, cutting tools are coated with materials possessing thermal insulation characteristics. Such coatings benefit machining, providing faster cutting speeds and tools life. However, the heating of the tools is still present. Therefore, this work simulates the transient heating phenomenon of a tool and its tool holder, considering the presence of the coating. The effects of convection, radiation, and contact resistance between the tool and the tool holder are also considered. The thermophysical properties of the tool elements depend on temperature. Experimental measurements of parameters related to contact resistance were carried out to make the thermal model closer to real situations. The COMSOL program was used to solve the heat diffusion equation using the Finite Element Method. Comparisons of calculated temperatures are presented for the uncoated (substrate only) and coated inserts with aluminum oxide (Al2O3) and titanium nitride (TiN), respectively. Finally, the results and the consequences of the assembly parameters in the fields of temperature and contact resistance are discussed.