ATOMIC-FORCE MICROSCOPY STUDY OF AN IDEALLY HARD CONTACT - THE DIAMOND(111) TUNGSTEN CARBIDE INTERFACE

A comprehensive nanotribological study of a hydrogen-terminated diamon d(lll)/tungsten carbide interface has been performed using ultrahigh v acuum atomic force microscopy. Both contact conductance, which is prop ortional to contact area, and friction have been measured as a functio n of applied load. We demonstrate for the first time that the load dep endence of the contact area in UHV for this extremely hard single aspe rity contact is described by the Derjaguin-Muller-Toporov continuum me chanics model. Furthermore, the frictional force is found to be direct ly proportional to the contact area.