The actual contact area and friction properties of elastomers under frictional contact with solid surfaces

Abstract

Using a specially designed apparatus simultaneous measurements were carried out of the area of contact and the friction between elastomers and solid surfaces. For a wide range of load, the friction force is proportional to the actual contact area and the friction constant depends only on the nature of the rubbing solids. In the range of low sliding velocities the actual contact area remains almost constant. At high sliding velocities increase of the friction force is associated with the process of the mechanical glass-transition of the surface layer of the cross-linked rubber which causes the actual contact area to decrease.