Off-stoichiometry-guided design of high-strength chemically complex intermetallic-based alloys with outstanding ductility

摘要

1.Introduction The lasting drive for improved energy efficiency in power gen-eration encourages the innovative design of advanced structural materials with superb mechanical properties[1-6].Among these materials,ordered intermetallic alloys[7-9],as a unique class of metallic materials,have drawn increasing concern from both the scientific and industrial communities due to their intriguing high-temperature properties,strong chemical binding,and low atomic mobility[10,11].However,in light of the insufficient number of slip systems and/or intrinsically weak grain boundary(GB),they are usually brittle at ambient temperature,severely hindering their practical use in engineering systems[12].Previous studies reported that the change in alloy stoichiometry has a significant beneficial effect on the ductility of intermetallic alloys.For instance,Liu et al.