Thermal deformation in frictionally heated contact

Abstract

When sliding occurs with significant frictional heating thermoelastic deformation may lead to a transition from smoothly distributed asperity contact to a condition where the surfaces are supported by a few thermal asperities. This circumstance may be associated with a transition to a condition of severe wear because of the elevated contact pressure and temperature, and also because of production of tensile stresses. This second stress component may lead to heat checking whereupon the rough checked surface acts to abrade the mating material. The factors influencing transition are discussed, including wear, cooling and hydrodynamic lubrication. The transition state is also discussed with regard to the stress distribution, rate of movement of the contact patches and temperatures.