Abstract: Based on the reciprocal law of thermal elastic and thermal expansive deformation caused by thermal parameters, the theoretical model of friction surface contact deformation is deduced. The idea of random combined algorithm proposed by Voss is used to establish the engineering rough surface by simulating the fractal Brownian motion. The simulated surface is combined with the theoretical model to describe the evolution rule of friction surface roughness. The research indicates that there is correlation between the contact deformation and thermal parameters; the case analysis reveals that the thermal parameters have dramatic effects on friction surface roughness and the degrees of effects of different thermal parameters are different. It can be seen from the curve of relationship between the parameter variation and the engineering surface roughness variation. In the thermal parameters, except that there is nonlinear relationship of inverse proportion between the thermal conductivity and the roughness variation, the variation of other thermal parameters is consistent with the variation trend of roughness, but the variation curvatures are of different sizes. Obviously, the degree of effect can be used to describe the dynamic evolution process of surface roughness of different materials in a tribological process.

Key words: Contact model, Fractal model, Friction surface, Thermal parameter