Microstructure and tribological behavior of multilayered CrN coating by arc ion plating

Multilayered CrN (M-CrN) coating was successfully prepared by arc ion plating method. The conventional CrN coatings were deposited under Ar + N2 working pressures of 7.8 × 10− 1 Pa and 1.6 × 100 Pa, namely P-CrN and R-CrN respectively, for comparing the tribological behavior. M-CrN coating shows the multilayered microstructure. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) measurements evidenced the different stoichiometry between the P-CrN and R-CrN layers. The experimental results show that wear resistance of the M-CrN coatings was much better than that of the conventional CrN coatings. Instead of bulk flake-off behavior, wear mechanism of the M-CrN coating is the micro-area detachment. That is because the multilayered microstructure can inhibit the formation of cracks extended into the substrate, with the high hardness, low coefficient of friction and high H/E value.