Application of Multifractal Spectrum Calculation Program in Rubber Wear Under High Temperature

Due to the complexity of the rubber wear process, the research work of the wear mechanism is limited to normal temperature, and the mechanism of high temperature wear has not been established. The temperature has great influence on the appearance of wear and the change of the surface characteristics of wear. This paper presents the wear surface morphology of rubber materials at different temperatures. The two-dimensional gray level images of the rubber surface are captured by a 3D measuring laser microscope and are converted to black-and-white binary images. Then, the quantitative analysis of the wear surface is processed using fractal dimension and the multifractal spectrum method. Results show that the wear rubber surface is fractal. Additionally, the roughness and the spectral width values increases with increase in temperature. Furthermore, the fractal dimensions shrink and the homogeneity of the rubber surface worsens. As temperature increases, the corresponding Δα and Δf(α) increase, resulting in rough wear surface with lower height homogeneity and higher complexity. Δα is equal to 0.238, 0.281 and 0.283 at the temperature of 25, 60 and 80 °C, respectively. Δf(α) is equal to 0.027, 0.035 and 0.039 at the temperature of 25, 60 and 80 °C, respectively. In conclusion, fractal theory can be used to describe and evaluate the surface morphology and wear characteristics of rubber materials.