Alloying and Processing Effects on the Aqueous Corrosion Behavior of High-Entropy Alloys

The effects of metallurgical factors on the aqueous corrosion behavior of high-entropy alloys (HEAs) are reviewed in this article. Alloying (e.g., Al and Cu) and processing (e.g., heat treatments) effects on the aqueous corrosion behavior of HEAs, including passive film formation, galvanic corrosion, and pitting corrosion, are discussed in detail. Corrosion rates of HEAs are calculated using electrochemical measurements and the weight-loss method. Available experimental corrosion data of HEAs in two common solutions [sulfuric acid (0.5 M H$_{2}$SO$_{4}$) and salt water (3.5 weight percent, wt.%, NaCl)], such as the corrosion potential (E$_{corr}$), corrosion current density (i$_{corr}$), pitting potential (E$_{pit}$), and passive region (ΔE), are summarized and compared with conventional corrosion-resistant alloys. Possible directions of future work on the corrosion behavior of HEAs are suggested.