Experimental investigation of the cutting temperature when turning with coated indexable inserts

This paper deals with an experimental investigation into the different factors which influence the temperature which occur at the coating/substrate-chip interface when machining a medium carbon steel and an austenitic stainless steel. Both flat-faced and grooved inserts coated with TiC; TiC/TiN and TiC/Al2O3/TiN were used. A standard K-type thermocouple embedded in the workpiece was used to convert measured efms to the interfacial temperature. Some optimal coating structures for high speed machining of these steels corresponding to the minimum interface temperature were selected. In particular, it was observed that by the proper selection of the thermal properties of the coating and the workpiece materials, which result in a substantial increase in the interface temperature, the effect of a thermal barrier in the top layer of the coating can occur. (C) 1998 Elsevier Science Ltd. All rights reserved.