The heat partition into cutting tool at tool-chip contact interface during cutting process: a review

Thermal load on cutting tool has a noteworthy influence on tool wear, tool life and machined surface quality. The heat partition coefficient into cutting tool characterizes the proportion of cutting heat flowing into it. This article provides an overview of the determining methods and influencing factors on the heat partition. Analytical modelling and hybrid FEM-experimental method are principal methods for identifying heat partition. The analytical models include uniform distribution and non-uniform distribution heat partition models. By reviewing influencing factors on the heat partition, it is found that thermal conductivities of workpiece and cutting tool, cutting speed and machining processes have greater influence on the heat partition compared with other influencing factors. The current researches on the determination of heat partition into cutting tool regard the tool-chip contact interfaces as perfect contact but not reveal true nature of the contact interface. The true contact only at the asperities at the tool-chip interface is observed through microscopic inspection. Oxide layer is generated on TiAlN coated tool rake face. Therefore, further research for the heat partition should consider the thermal contact resistance due to the non-perfect contact at tool-chip interface and the oxide layer generated on tool rake face.