Effect of Thermal Properties of the Coupled Tool/Work Materials on the Tool-Chip Interface Behaviour
The basic objective of this paper is to develop an alternative methodology for thermophysical-property-based modelling of the tool-chip interface behaviour resulting from steel-coating/substrate interaction. For this reason extended experimental investigations of the contact temperature, the tool-chip contact length and heat transfer during orthogonal cutting of AISI 1045 carbon and AISI 304 austenitic stainless steels were carried out. Carbide cutting tool inserts coated with TiC/Al2O3/TiN- TiC/TiCN/Al2O3/TiN-multilayer and TiAlNhard films were used. The modelling procedure was based on the dependence of the process performance on the thermal conductivity, the thermal diffusivity, the heat transmission coefficient and the modified Pèclet number. The obtained results can be used in proper selection of coated tools for desired machining requirements. It is possible, by considering temperature-dependent properties of the coupled materials and changes in tool-chip contact length values, to control the heat flow in the substrate/coating-chip system.
cutting, protective coatings, tool-chip interface, contact temperature, heat flow.