Friction Between Steel and Snow in Dependence of the Steel Roughness

The purpose of this study was to analyze the effect of the surface structure on the friction between steel and snow. On a linear tribometer positioned inside a cold laboratory, four steel skis with different running surfaces were tested over a wide range of velocity, snow temperature and normal force. The surface roughness was measured with a focus variation microscope. The friction tests showed that the surface roughness had a major effect on friction between steel and snow, with higher friction for smooth surfaces than for rough ones. The effect was particularly strong for temperatures close to the melting point, where the friction strongly increased for smooth surfaces. The degree of dependence was affected by the gliding speed, leading to two different kinds of velocity-dependent friction curves. Increased adhesion and wet friction due to an increase in contact area were interpreted as cause for the higher friction of smooth surfaces.