Effect of surface temperature rise on friction characteristics for sliding speed under unlubricated condition

Abstract

This article presents a theoretical model of the kinetic friction characteristics for sliding velocity under mild wear condition, assuming a simple effective hardness at asperity contacts. The proposed model depends on the surface temperature distribution obtained by using Jaeger's estimation for a moving homogeneous heat source with an infinitely long band on a semi-infinite solid and a relation between steel hardness and temperature measured by Tominaga. Further, the model takes into consideration the stochastic model of a rough surface contact that was proposed by Greenwood and Williamson. The calculation results show that the surface temperature increases and the surface hardness and the friction coefficient decrease as the sliding velocity increases. However, the variation in the friction coefficient is less than that in the surface hardness. The initial value of the friction coefficient and the contact pressure has a great influence on the relation between the friction coefficient and the sliding velocity. In contrast, the standard deviation of the asperity summit heights has little influence on the relation.

A new asperity interaction model considering transient flash temperature and inhomogeneous distribution of oil viscosity

“…This may be because the higher velocity induces the higher temperature, lower hardness of the asperity, and lower viscosity of the lubricant that cause lower friction coefficient. 29 Besides, due to the lower oil film load capacity after considering the variation of viscosity, friction coefficient changes at the same velocity. And the influence of inhomogeneous distribution of viscosity on friction coefficient increases first (from V ¼ 1 m/s to V ¼ 3 m/s) and then decreases (from V ¼ 3 m/s to V ¼ 5 m/s) with the increase of velocity, which is the result of the increase of transient flash temperature and the decrease of the ratio of the fluid-solid interaction to solid-solid contact.…”

Friction Induced Wear of Rapid Prototyping Generated Materials: A Review

“…This is mainly due to the fact that polymers are far more prone to thermal effects observed during dry sliding/fretting, and it is well known that friction mechanisms are significantly affected by the developing thermal field in the material contact area [46,47]. Hence an increase of sliding velocity during friction tests will elevate the temperature of the counter-bodies interface and thus is expected to reveal intense wear progression [48].…”