Anisotropic tribological properties of SiC

Abstract

The anisotropic friction, deformation and fracture behavior of singlecrystal SiC surfaces were investigated in two categories. The first is that in which friction and wear of SiC arises primarily from adhesion between sliding solid surfaces in contact and the second is where friction and wear of SiC occur as a result of the surface sliding against a hard particle. The categories are called adhesive and abrasive wear processes respectively. In the adhesive wear process the adhesion, friction and wear of SiC are markedly dependent on crystallographic orientation. The force to re-establish the shearing fracture of an adhesive bond at the interface between SiC and a metal is the lowest in the preferred orientation of the SiC slip system. The fracturing of SiC occurs near the adhesive bond to the metal and it is due to primary cleavages of both prismatic {101̄0} and basal {0001} planes. In the abrasion process of SiC the 〈101̄0〉 direction on the basal plane exhibits the lowest coefficient of friction and the greatest resistance to abrasion for SiC. The anisotropic friction and plastic deformation are primarily controlled by the slip system {101̄0} 〈112̄0〉. The anisotropic fracture in the abrasion process is due to primary cleavages of {0001}, {101̄0} and {112̄0} planes.