Friction at high sliding speed of WC-6Co pin versus steel disc AISI 1045: estimation of the contact temperature

Abstract

Cemented carbide based cutting tools remain widely used in machiningprocesses for their wear resistance. Knowledge and modelling of wearprocesses are of prior importance to get models to predict and increasethe cutting tool service life. The present paper deals with some results of aresearch work that study relationships between wear and temperature inthe case of pin-on-disc tribological experiments. Topic of the paper isfocussed on the estimation of the pin/disc contact temperature bycoupling experimental measurements and computational methods.Friction experiments are conducted with WC-6Co pins against steeldiscs made of an AISI 1045 grade. Furthermore, WC-6Co pins areinstrumented with two type-K thermocouples. A large sliding velocity rangeis considered in the study: from 100m/min up to 600m/min. The presentpaper is focussed on the 600m/min velocity. During these tribological tests,tangential forces and thermocouple temperatures are measured andmonitored. From these values, the heat flux in the WC-6Co pin is estimatedby two different ways. On one hand by considering the unidirectionalFourier law, on the other hand by estimating the heat partition coefficient [1]between the disc and the pin. The heat partition coefficient is determinedfrom a physical approach based on the consideration of the mechanicalpower dissipated in the contact. In both cases, the heat transfer in the pinis then modelled by finite element methods. It is necessary to performnumerical analysis to estimate the pin/disc interface temperature becauseof the impossibility to measure it directly during friction tests. Results ofexperiments and of numerical simulations are compared.