Influence of Energy Nitrogen Ion Implantation on Structural and Mechanical Properties of Chromium Thin Film

Chromium thin films were deposited on 304 stainless steel using the hollow cathode discharge (HCD) method. Chromium films were implanted with nitrogen ions at different energies ((15-25-35-45) keV) and at a dose of 5×1017ions/cm2. The implanted films were characterized using x-ray diffraction (XRD), atomic force microscopy (AFM), microhardness testing, friction coefficient measurements, and wear mechanism study. The XRD results confirmed that increasing energy does not effect the formation of the CrN phase. AFM images showed that surface roughness changed proportionally to grain size after implantation. It was found that hardness increased as energy increased. From the friction coefficient measurement, it could be inferred that the friction coefficient decreased as energy increased. The wear mechanism for the un-implanted sample was abrasion, but it shifted to delamination and adhesive as energy increased