The role of surface carbon contamination on the tribological properties of ion-implanted 100Cr6 bearing steel

Samples of 100Cr6 bearing steel were implanted with nitrogen and boron in order to study the evolution of their tribological properties. Even though, the physico-chemical characterizations show an important modification of the nature of the sample surfaces after B and N ion implantation, the tribological tests do not exhibit any significant change of friction. However, on a set of samples accidentally contaminated with carbon during ion implantation, friction was highly improved. We then decided to continue this kind of surface treatment but by provoking deliberately a carbon pollution not only during B and N ion implantations but also during separate Ne ion irradiations. The tribological tests reveal a clear improvement of friction (by a factor of 5) whatever the implanted ion.