Predictive modelling of average heat partition in high speed machining of AISI/SAE 4140 steel

Heat partition and cutting temperatures affect tool performance, tool wear mechanisms, and quality of the machined part in high speed machining (HSM). In this study, heat partition in the secondary deformation zone is determined by using analytical and finite element models for turning with uncoated and TiN coated tools. Numerical and experimental results are used to calculate the amount of heat entering the tool for conventional to HSM of AISI/SAE 4140 steel. This paper elucidates on the thermal properties of the tool and the workpiece materials, process variables, and contact phenomena in predicting heat partition. Results show that TiN coating enables a significant reduction in the tool-chip contact area, heat generation, tool-chip interface temperatures, and the amount of heat entering the cutting tool. More significantly, the results show that the reduction in heat partition due to TiN coating is more pronounced in HSM compared to conventional machining.