Mechanical Properties and Corrosion Resistance of NbTiAlSiZrN High-Entropy Films Prepared by RF Magnetron Sputtering.

In this study, we designed and fabricated NbTiAlSiZrN high-entropy alloy (HEA) films. The parameters of the radio frequency (RF) pulse magnetron sputtering process were fixed to maintain the N flux ratio at 0%, 10%, 20%, 30%, 40%, and 50%. Subsequently, NbTiAlSiZrN HEA films were deposited on the 304 stainless steel (SS) substrate. With an increasing N flow rate, the film deposited at a R of 50% had the highest hardness (12.4 GPa), the highest modulus (169 GPa), a small roughness, and a beautiful color. The thicknesses of the films were gradually reduced from 298.8 nm to 200 nm, and all the thin films were of amorphous structure. The electrochemical corrosion resistance of the film in a 0.5 mol/L HSO solution at room temperature was studied and the characteristics changed. The HEA films prepared at N flow rates of 10% and 30% were more prone to corrosion than 304 SS, but the corrosion rate was lower than that of 304 SS. NbTiAlSiZrN HEA films prepared at N flow rates of 20%, 40%, and 50% were more corrosion-resistant than 304 SS. In addition, the passivation stability of the NbTiAlSiZrN HEA was worse than that of 304 SS. Altogether, these results show that pitting corrosion occurred on NbTiAlSiZrN HEA films.