Effect of mixed N and Ar implantation on tribological properties of tool steel

The change of the tribological properties after ion implantation of two kinds of tool steels: chromium-NC11LV and chromium free-N11E was studied. Nitrogen and argon implantations were carried out in different orders at energy 120 keV with the doses 5×1017 and 1×1017ions/cm2, respectively. Significant improvement of abrasive wear and friction coefficient as well as microhardness of NC11LV steel was observed. The order of mixed implantation influenced on wear and microhardness. The best results were obtained for Ar+ implantation prior to N2+. Ion beam implantation causes decrease of grain size and increase of microstrain. There is no clear improvement of tribological properties of chromium-free N11E steel after implantation regardless of implanted ions and order of implantation. Microhardness and resistance to abrasive wear usually increases insignificantly but the friction coefficient increases also in all the cases.