Corrosion-resistant high entropy alloy with high strength and ductility

High strength materials lack a synergistic combination of mechanical properties and corrosion resistance desired for most structural applications. Phase and grain boundary architecturing is done in the material to attain balance in these properties. A friction stir processed Fe35.5Mn20Co20Cr15Si5Cu1.5 (Cu-HEA) exhibited excellent mechanical properties and high corrosion resistance in synergy. The excellent mechanical properties were attributed to the controlled transformation of ultrafine gamma matrix and epsilon twinning; whereas good corrosion resistance was due to homogenized fine grained gamma microstructure. In short, Cu-HEA design opens a new pathway towards realizing strong and ductile alloys with tunable corrosion resistance by engineering matrix metastability. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.