Study of frictional sliding and defect density in the wear of bearing steel

Sliding wear tests with pin-on-disk configuration were performed on AISI 52100 steel under various applied loads. The Doppler broadening peak parameter of positron annihilation, which is often a measure of the concentration of point defects, was used to measure the degree of plastic deformation in the worn specimens. The dependence of the peak parameter and the coefficient of friction on load were observed to be similar. A simple theoretical analysis was attempted to derive the functional relation between the coefficient of friction and the defect density, and the resulting equation agrees with the experiments.