Effect of Boron on the Corrosion Properties of Al0.5CoCrCuFeNiBx High Entropy Alloys in 1N Sulfuric Acid

Abstract

High entropy alloys are a newly developed family of multi- component alloys composed of several major alloying elements, such as copper, nickel, aluminum, cobalt, chromium, iron, etc. Each element in the alloy system is between 5 at.-% and 35 at.- %. High entropy alloy has a lot of advantages regarding its mechanical, magnetic and electrochemical properties. This study discusses the corrosion resistance of Al0.5CoCrCuFeNiBx alloys with various amounts of boron addition. Surface morphology and EDS analysis confirmed that the addition of boron produced Cr and Fe borides. Therefore the content of Cr in the region besides borides precipitates was very scanty. The anodic polarization curves and electrochemical impedance spectra of Al0.5CoCrCuFeNiBx alloys, obtained in 1 N H2SO4 aqueous solution, clearly indicated that the general corrosion resistance decreases as the amounts of boron increases.