Prediction of heat partition in metal cutting - A state-of-the-art review of conventional to high-speed machining

Temperature and heat partition along the tool rake face are critical parameters that influence the metal cutting process and thus determine machining quality and tool stability, especially in high-speed cutting. Therefore, determining and reducing the temperature along the tool rake face is of particular importance in machining. The problem has been approached in numerous ways, including experimental, analytical, and numerical analysis. Although considerable research exists on the thermal problem in metal cutting, there is little agreement on the basic principles, which makes it extremely difficult to predict heat partition in a precise manner. This chapter first presents a comprehensive review of previous research on heat generation and heat partition in orthogonal machining at speeds ranging from conventional to high-speed machining (HSM). The next section evaluates experimental methods and various analytical approaches for determining the fraction of heat flowing into the tool from the secondary deformation zone. The final section discusses the Finite Element Method (FEM), which may be applied in conjunction with the experimental data to predict the amount of heat entering into the tool. This application has been demonstrated for conventional to HSM of AISI/SAE 4140 high strength alloy steel with uncoated, as well as TiN and TiAlN-coated tools. It is concluded that existing models are quantitatively inadequate for predicting heat partition into the cutting tool, particularly in high-speed machining. Moreover, it is proposed that important thermal properties of the tool and the workpiece, cutting process variables, and contact phenomena should all be considered in predicting heat partition.