Fabrication of hydrophobic AlCoCrFeNi high-entropy alloy and superior corrosion resistance to NTO aqueous solution

Hydrophobic AlCoCrFeNi high-entropy alloy (HEA) was prepared by electrochemical dealloying using 5% of weight percent H2SO4 aqueous solution at low temperature. The results of energy-dispersive spectrometer (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed that the element contents of Al and Ni were greatly reduced after dealloying treatment, leading to the increase of body centered cubic (BCC, Fe-Cr) phase and consequently, the achievement of the protective barrier of Cr- enriched oxide film on the substrate surface. The static water contact angle increased with the extension of dealloying period and reached a maximum value of 127 +/- 1 degrees, showing pronounced hydrophobic performance after dealloying treatment. Meanwhile, the AlCoCrFeNi HEA specimens showed excellent mechanical properties involved compressive strength and micro-hardness. Compared with the as-cast AlCoCrFeNi HEA, the HEA specimens after dealloying treatment exhibited superior corrosion resistance in an acidic aqueous solution of 3-nitro-1, 2, 4-triazole-5-one (NTO) aqueous solutions confirmed by potentiodynamic polarization tests and electrochemical impedance spectra (EIS) analyses, which was credited to the Cr- and Fe-enriched oxide and hydrophobic surface. Data Availability: The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study. (c) 2022 Elsevier B.V. All rights reserved.