Thermal characterization of the chip-tool interface when using coated turning inserts

This paper reports some results of extensive experimental investigations of the thermal interactions between the coating/substrate and the moving surface of the chip. Semi-orthogonal cutting when bar turning a medium carbon steel and an austenitic stainless steel was carried out. Both flat-faced and grooved inserts coated with TiC, TiC/TiN, and TiC/Al2O3/TiN were tested. A standard K-type thermocouple embedded in the workpiece was used to convert measured efm's to the interfacial temperatures. In addition, the chiprake contact length and the area of contact were determined by using computer processing of scanned contact images. The minimum steady-state temperature at the interface between the moving chip and the coating-substrate system was explained in terms of the heat flux intensity and the thermal properties of both components of a unique closed tribo-system. Copyright © 2012 Elsevier B.V.