Porosity Ratio and Anti-Corrosion Properties of Cr/CrN Films Synthesized by Unbalanced Magnetron Sputtering

In the present paper, Cr, CrN single-layer films and Cr/CrN multilayer films were deposited on iron and silicon wafer substrates by means of unbalanced magnetron sputtering. The film thickness was measured using surface profile meter. The porosity ratio was calculated using coulometric method based on the polarization curves obtained in the 30g/L NaCl solution at room temperature. Moreover, the corrosion resistance of the sample in a 350°C water vapor atmosphere was also analyzed. The thickness of all films ranged from 1.03 to 1.54 micrometer. The porosity ratio of the Cr and CrN single-layer film were 3.72% and 5.83%, respectively. The porosity of the Cr/CrN multilayer film decreased to 0.39%. The results showed that the Cr/CrN multilayer films had better protection than the Cr and CrN single-layer films.