Process parameter optimization and corrosion properties of the AlCrTiV medium entropy alloy films

In this work, based on an orthogonal experimental design, nine groups of the AlCrTiV medium-entropy alloy (MEA) films were prepared by vacuum magnetron sputtering under different deposition parameters (sputtering power, substrate temperature, and bias voltage), and the influence of deposition parameters on their corrosion property (in 3.5 wt % NaCl solution) was studied in detail. Through range analysis, we identified the optimal process parameters for achieving superior corrosion performance (sputtering power of 800 W, substrate temperature of 400 °C, bias voltage of 100 V). The research results indicate that the sputtering power has the greatest impact on the corrosion properties of the films. Specifically, corrosion resistance diminishes as power increases, with the optimal corrosion resistance observed at 800 W. After corrosion, the surfaces of the films are composed of the oxidized state and the unoxidized state of the metal, and the corrosion mechanism is pitting. The enrichment of Cr and O elements in the pitting pores may be related to the rupture and regeneration of Cr₂O₃ in the passivation film. The XPS results suggest that enhanced corrosion resistance correlates with a higher concentration of Al₂O₃ and Cr₂O₃ in the dense passivation film.