Characterization of friction coefficient and heat partition coefficient between an AISI4140 steel and a TiN-coated carbide – influence of (Ca, Mn, S) steel's inclusions

Abstract

This work aims at characterizing the influence of Ca—Mn—S inclusions in an AISI4140 steel (280 HB) during friction against a TiN-coated carbide under extreme conditions. A specially designed open tribometer has been used to characterize the friction coefficient and heat partition coefficient at the contact under specific extreme contact conditions simulating those occurring at the tool—chip—workpiece interface in dry cutting. It has been shown that sliding velocity is the most influential parameter. A great decrease of the friction coefficient and heat partition coefficient is observed under high sliding velocities. Moreover, it has been revealed that inclusions lead to a great decrease of friction at low sliding speeds, irrespective of contact pressure. On the contrary, under high sliding velocities, there is no significant influence of inclusions. Additionally, it has been observed that inclusions are not able to modify the heat partition coefficient at the interface. Finally, this work provides quantitative data of the friction coefficient and heat partition coefficient versus sliding velocity and contact pressure in order to be implemented in any analytical and numerical model.