The frictional anisotropy of diamond

摘要: This paper describes a study of the friction, in air, spherically tipped diamond stylus over {100} face flat surface. The results show that general friction is greater when sliding occurs along direction than direction. cannot be explained terms Coulomb frictional mechanism where attributed to climbing one surface asperities on other, for case coefficient determined solely by topography and independent load. By contrast, experiments described this below critical load Wc anisotropy virtually disappears. proportional R 2 , radius curvature stylus, implying, Hertzian deformation, contact pressure. For both type I II diamonds pressure has value order 20 GN m -2 . At these larger pressures cathodoluminescent studies surfaces indicate largely due sub-surface damage produced preferred crystallographic directions process itself. are discussed crack formation plastic deformation. However, do not, as yet, provide an unequivocal account energy dissipation.