A review on Corrosion of High Entropy Alloys: Exploring the Interplay Between Corrosion Properties, Alloy Composition, Passive Film Stability and Materials Selection
Camila Boldrini Nascimento, Uyime Donatus, Carlos Triveño Ríos, Mara Cristina Lopes de Oliveira, Renato Altobelli Antunes
Abstract
The corrosion resistance of high entropy alloys was reviewed in the present work. The main focus was to explore the correlation between alloy composition, passive film stability and corrosion properties and use this information to develop a materials selection procedure based on the Ashby approach. Corrosion current densities and pitting potentials were the main design parameters used to rank different alloys, based on a careful examination of data published in the literature, considering uniform and localized corrosion, respectively. The outputs of the selection process clearly indicated a strong dependence of the corrosion resistance on passive film stability, although microstructural homogeneity and uniform distribution of alloying elements should not be disregarded. Proper combinations of elements such as Co, Al, Ti, Mo and Cr, especially, are effective at enhancing the corrosion resistance of high entropy alloys.