Microstructure and chloride corrosion property of nanocrystalline AlTiCrNiTa high entropy alloy coating on X80 pipeline steel

Five-target magnetron sputtering was used to prepare an AlTiCrNiTa high-entropy alloy (HEA) coating on an X80 steel substrate. The phase, morphology, and composition of the as-deposited coating were investigated by using XRD, SEM, AFM, and EDX. Moreover, its corrosion resistance in 3.5 wt% NaCI solution was studied by electrochemical methods. The obtained results indicate that the AlTiCrNiTa HEA coating exhibited a single BCC fine nanocrystalline structure, which can effectively improve the corrosion resistance of X80 steel in 3.5 wt% NaCI solution. After electrochemical corrosion, the AlTiCrNiTa HEA coating still effectively maintained an integrated and dense surface. The mechanisms behind the development of corrosion resistance in the AlTiCrNiTa high-entropy alloy coating are evaluated in detail.