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

Abstract

In this study, we designed and fabricated NbTiAlSiZrNx high-entropy alloy (HEA) films. The parameters of the radio frequency (RF) pulse magnetron sputtering process were fixed to maintain the N2 flux ratio at 0%, 10%, 20%, 30%, 40%, and 50%. Subsequently, NbTiAlSiZrNx HEA films were deposited on the 304 stainless steel (SS) substrate. With an increasing N2 flow rate, the film deposited at a RN 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 H2SO4 solution at room temperature was studied and the characteristics changed. The HEA films prepared at N2 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. NbTiAlSiZrNx HEA films prepared at N2 flow rates of 20%, 40%, and 50% were more corrosion-resistant than 304 SS. In addition, the passivation stability of the NbTiAlSiZrNx HEA was worse than that of 304 SS. Altogether, these results show that pitting corrosion occurred on NbTiAlSiZrNx HEA films.

Research Progress of Titanium-Based High Entropy Alloy: Methods, Properties, and Applications

“… Liang et al (2011) found that in the nitrogen flow rate of 4 SCCM, the hardness and elastic modulus of (TiVCrZrHf)N coatings reach respectively to their maximum values of about 23.8 ± 0.8 and 267.3 ± 4.0 GPa. Furthermore, the corrosion resistance of the NbTiAlSiZrNx HEA coating was prepared by Xing et al (2019) under the various nitrogen flow rates is significantly different from that of 304 stainless steel. Lukáè et al (2020) prepared the HfNbTaTiZr HEA film that presents a nano-cell structure with fine surface microstructure and uneven distribution of defects by DC magnetron sputtering.…”

Corrosion Properties of Cr27Fe24Co18Ni26Nb5 Alloy in 1 N Sulfuric Acid and 1 N Hydrochloric Acid Solutions

“…Al 0.5 CoCrCuFeNi alloy coating the surface of AZ91D by laser cladding successfully improved the corrosion resistance in 3.5 wt.% sodium chloride solution [10]. NbTiAlSiZrN x alloy thin films sputtered on 304 stainless steel exhibited good corrosion resistance in 1 N H 2 SO 4 solution [11]. Coatings of AlCr x NiCu 0.5 Mo (x = 0, 0.5, 1.0, 1.5, 2.0) alloys significantly improved the corrosion resistance of Q235 steel in 3.5% NaCl solution and a salt spray corrosion environment [12].…”

Recent Progress on High-Entropy Films Deposited by Magnetron Sputtering

“…However, this rule cannot be generalized. Some HEFs remain amorphous, even after increasing the nitrogen content, such as in the case of NbTiAlSiZr [79], AlCoCrNi [27], FeCoNiCuVZrAl [68] and AlBCrSiTi [84] nitrides films. Liu et al explain that the amorphization tendency could result from the low enthalpy of the mixed elements, the difference between the depositing temperatures and also from a large solid/liquid interface energy [68].…”