Ice friction, wear features and their dependence on sliding velocity and temperature

Friction processes for ice samples sliding on steel have been determined by examining wear and debris morphology with low-temperature scanning electron microscopy and relating the processes to the velocity and temperature of formation. Friction experiments were carried out over a temperature range of -27 to -0.5 degrees C and velocity range of 0.008-0.37 m s(-1). Data were used to develop a friction map. Low friction (mu < 0.1) at high temperature (-3.4 degrees C)-low velocity (0.02 m s(-1)), and low temperature (-25.1 degrees C)-high velocity (0.30 m s(-1)) is due to the presence of liquid water which lubricates the sliding interface. Diagnostic morphologies for lubricated sliding include the presence of residual liquid in wear grooves and the development of a consolidated mass of debris on the trailing side of the wear surface with distinct grain boundaries and spheroidal air bubbles. High friction (mu>0.15) at low temperature (-24.5 degrees C)-low velocity (0.03 m s(-1)) results from insufficient lubrication at the sliding interface, leading to plastic deformation. Diagnostic morphologies of plastic deformation include scuffing features on the wear surface and the accumulation of sheets of unconsolidated debris on the trailing edge of the wear surface.