FRETTING WEAR OF CARBON-ION-IMPLANTED PHYSICAL-VAPOR-DEPOSITED TIN COATINGS

Titanium carbonitride top-layers were prepared by selectively implanting 80 keV C+ ions into a physical-vapour-deposited TiN coating 2.8-mu-m thick. Rutherford-backscattering analysis showed that the implanted carbon depth distribution was the one predicted by the TRIM 87 calculation and that part of the implanted carbon had diffused out from the gaussian-like distribution towards the surface, where an ion-beam-assisted deposition of an ultrathin carbon overlayer had grown. For doses going from 2.8 x 10(16) to 7.8 x 10(16) ions cm-2 the effect of the carbon implantation on the fretting wear behaviour was investigated. Friction and wear measurements demonstrated a well-defined difference between as-plated TiN and carbon-implanted TiN. Related to the carbon implantation, it was observed that a low friction coefficient during break-in corresponds to a lower fretting wear damage.