Corrosion resistance improvement of multi-principal element alloy by tailored structure with heterogeneous grains

The Co40Cr20Ni30Al5Ti5 multi-principal element alloy (MPEA) with heterogeneous grain structure (HGS) and nano L12 precipitates is successfully designed by cold rolling and proper heat treatment. The HGS alloy exhibits excellent corrosion resistance and passiv-ation performance, originated from high-density grain boundaries in fine grains and abundant defects in deformed grains, which encourages surface to form a thicker and more efficient passive layer to inhibit the initial pitting corrosion. This finding indicates that the developed MPEA with HGS can possess an excellent combination of corrosion resistance and mechanical properties, providing highly positive factors for future applications.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).