Abstract:

Low friction is the most outstanding feature of ice surface. The existence of liquid water on ice surface, which serves as lubricant, has been taken as the main cause for its low friction. Three main hypotheses for the formation of liquid water on ice surface were introduced and analyzed. It was found that the pressure-melting, friction heat-melting and pre-melting theories cannot give satisfactory explanation to all facts. Based on the previous studies, it was clear that the formation of liquid water was not the only reason for explaining the low friction of ice. A new model that there is a transition layer with small ice particles and liquid water forming a gel-like amorphous structure on the ice surface is proposed. Owing to the weak interaction between these small ice particles, they can easily slide or rotate along the shear direction and thus reduce friction. Both the rotation of ice particles and lubrication of liquid water benefit excellent slipperiness of ice surface.

Key words: Ice surface, Low frictional efficient, Surface structure of ice, Transition layer