FRICTION TRACKS ON DIAMOND SURFACES IMAGED BY ATOMIC-FORCE MICROSCOPY

The friction tracks produced by spherical diamond styli sliding on a p lanar diamond face along a soft direction for polishing have been imag ed by atomic force microscopy. The tracks produced by a single pass as well as by multiple passes of the stylus show the presence of many in dividual smooth grooves, which are only a few atom layers deep. Debris formed during the sliding process was always found along the paths. T he tracks produced at high loads show the presence of ring cracks as w ell as grooves. The morphology of the grooves indicates that wear is a process during which atoms are removed individually or in small group s. Implications for understanding the mechanism of diamond perishing a re discussed. (C) 1997 Elsevier Science S.A.