Atomistic Consideration of Frictional Force (1st Report)

Abstract

This paper describes a fundamental concept of friction from atomistic aspect and the calculation of frictional force based on the proposed concept in an elastic contact condition. Assuming that interatomic bonds arise at the interface between the solid surfaces in elastic contact, friction is understood by the behavior of the interfacial atoms. The chemical bonds also arise at the interface between two solid surfaces in contact, and the exchange of bonds is induced at the time of relative displacements. Therefore, the frictional energy is a released interatomic strain energy at the time of exchange of bonds. Thus the frictional energy and force of fcc metals can be calculated based on the proposed concept in an elastic contact condition. The results of calculation may be summarized as follows. Assuming that the contact area is constant, the frictional force is not influenced by contact pressure in an elastic contact condition. Assuming also that interatomic potential is Morse potential, frictional force is dependent on the lattice orientation, but independent on sliding direction. In the case of fcc metals, the values of frictional force is strongly correlated with those of critical shear stress.