EVIDENCE FOR A STRONG CORRELATION BETWEEN THE AMOUNT OF SURFACE CARBON AND THE TRIBOLOGICAL BEHAVIOR OF ION-TREATED STEELS

Samples of 100Cr6-bearing steel were treated by different ion beams in order to study the evolution of their tribological properties. Comple mentary physico-chemical characterisation techniques give evidence for a strong correlation between the amount of surface carbon, whatever i ts origin (contamination, direct C implantation or ion beam mixing of a deposited carbon layer), and the reduction of the friction coefficie nt as well as the increase of the wear resistance. It is found that th e friction coefficient is improved by a factor 5 and the wear volume b y two orders of magnitude when the amount of surface carbon exceeds 10 (17) C cm(-2).