Corrosion Resistance of TiCN Films Prepared with Combining Multi-arc Ion Plating and Magnetron Sputtering Technique

TiCN films were deposited on AISI 304 stainless steel substrate by combining multi-arc ion plating and magnetron sputtering technique with ionizing titanium and graphite targets in an Ar+N-2 mixture gas. The effect of duty ratio on the microstructure and corrosion resistance of TiCN films in a NaCl 3.5 wt% solution was investigated. The results show that the as-deposited films exhibit smooth, uniform and dense morphologies, mainly forming a fcc-TiN type structure with Ti-(C, N) bond as well a as few alpha-CNx, and present (111) preferred orientation with the increase of duty ratio. TiCN films display a better resistance to corrosion than the bare substrate; as the duty ratio increases, the corrosion resistance is enhanced gradually. When the duty ratio is 40%, the TiCN film shows the optimal corrosion resistance with a corrosion current density (i(corr)) of 3.262 X 10-(7) A.cm(-2) and a polarization resistance (R-p) of 238.4 k Omega.cm(2). Electrochemical impedance spectroscopy (EIS) of the films also indicates that the penetration behavior of corrosive ions and the local corrosion process are two key factors affecting the electrode corrosion reaction kinetics process, which is consistent with the polarization curves analyses.