Development of oxidation-resistant L12-strengthened medium to high entropy alloys for additive manufacturing

This study investigates the oxidation kinetics of a newly designed L1 2 -strengthened medium entropy alloy (MEA) and high entropy alloy (HEA) produced by additive manufacturing and compares them with commercially available IN718 and MAR-M247 alloys. Isothermal oxidation tests at 900 °C to 1100 °C, a cyclic oxidation test at 1100 °C, and subsequent microstructural analysis revealed that the designed MEA and HEA exhibited excellent oxidation resistance with much lower weight changes than IN718 without any crack-induced oxides as observed in MAR-M247. The superior oxidation resistance of the designed alloys is attributed to the preparations of crack-free samples that form a protective and uniform α-Al 2 O 3 layer. In the present work, the design for alumina-forming L1 2 -strengthened HEAs with an optimal combination of oxidation resistance and 3D printability is also discussed. • The novel 3D printable L1 2 strengthened MEA and HEA were designed. • The α-Al 2 O 3 forming newly designed alloys demonstrated good oxidation resistance compared to IN718 and Mar-M 247. • The effects of alloy composition on oxidation resistance and printability were discussed.