Flash Temperature on the Asperity Scale and Scuffing

A simulation model is described for determining the distribution of asperity flash temperatures when rough surfaces undergo relative sliding. The asperities are assumed to deform elastically and to have coulomb friction at their tips. The spherical asperity model of Greenwood-Williamson is joined with the flash temperature approximation formulas developed by Kuhlmann-Wilsdorf. Two example applications illustrate the effect of sliding speed and material role reversal on mean flash temperature. The model is applied to scuffing tests on ground and polished roller specimens reported in the literature. The predicted flash temperature is found to vary inversely with the experimentally observed scuffing loads within each finish type. For the same rolling and sliding speeds, the ground specimens had a lower observed scuffing load and a higher predicted mean flash temperature than the smoother polished specimens.