A fractal analysis of adhesive wear at the contact between rough solids

Abstract

This paper describes a theoretical study of adhesive wear at the contact between surfaces with nanometric level asperities and at low loads in order to arrive at predictive formulations that also take into account the effect of scale-dependent surface topography. The analysis of adhesive wear is closely associated with that of adhesion. Adhesive bonds may occur at the peaks of nanometric size asperities even though the microscopic roughness would inhibit the surfaces from approaching close separation. In order to account for the effect of asperities ranging from nanometer to micrometer level a fractal approach is used in the present analysis. The results broadly confirm the dependence of wear volume on normal load and also on adhesion arising out of surface forces. It also seems that the variation of fractal dimension and fractal adhesion indices may produce extreme conditions like very high wear even under tensile load or near zero wear which is certainly advantageous in practical situations.