Analytical model of thermal contact resistance generated at tool-chip contact interface during cutting H13 hardened steel with TiAlN coated tools

Thermal contact resistance (TCR) at tool-chip contact interface is caused by the incomplete tool-chip contact and the oxide layer formed on tool rake face. Value of the TCR characterizes the difficulty of transferring cutting heat from chip to cutting tool. This paper aimed at establishing an analytical model for quantifying the TCR. Firstly, two models were developed to calculate values of the TCR caused by incomplete contact and that caused by oxide layer, respectively. A total TCR analytical model was established to describe the relationship between the two models. Secondly, orthogonal cutting experiments of H13 hardened steel machined by TiAlN coated tool were conducted. Value of the TCR was quantified by the established model with cutting experimental results. At last, heat transfer experiments were carried out to verify correctness and applicability of the model. Different cutting speeds and workpiece materials verified and broadened the applicability of the model. Therefore, the analytical model was applicable to TiAlN coated tool cutting experiments. It provides a possibility for predicting cutting tool temperature accurately.