Wear behaviour of CrN coatings MEVVA ion implanted with Zr

CrN films deposited by a commercial physical vapour deposition (PVD) process were implanted with Zr ions by metal vapour vacuum arc (MEVVA) implantation at an energy of 40 keV and with doses ranging from 6×1016 to 2×1017 ion/cm2. The films were characterised by glancing incident angle X-ray diffraction (GIXRD), optical microscopy and scanning electron microscopy (SEM). Friction and wear tests were carried out using a pin-on-disc tribometer with a 6 mm diameter ruby pin. X-ray photoelectron spectroscopy (XPS) results show the formation in the implanted zone (IZ) of ZrN/CrZrN. X-ray diffraction (XRD) shows evidence of crystal damage, which increases with dose. The post-deposition process has induced only small changes in the friction behaviour of the CrN film, and overall the tribological properties were not enhanced. Nano-hardness measurements show that implantation has caused softening of the IZ layer. The tribological behaviour is explained in view of these results.