Dissimilar welding of Al0.1CoCrFeNi high-entropy alloy and AISI304 stainless steel

High-entropy alloys (HEAs) have been proven to exhibit superior structural properties from cryogenic to high temperatures, demonstrating their structural stability against the formation of complex intermetallic phases or compounds as major fractions. These characteristics can find applications in nuclear and aerospace sectors as structural materials. As the dissimilar joint design is necessary for such applications, an attempt is made to fabricate the dissimilar transition joint between Al0.1CoCrFeNi-HEA and AISI304 austenitic stainless steel by conventional tungsten inert gas welding. Microstructural characterization by SEM and EBSD clearly revealed the evolution of columnar dendritic structures from the interfaces and their transformation to equiaxed dendritic grains as they reach the weld center. Also, considerable grain coarsening was observed in the heat-affected zone of the HEA. The tensile test results depict that the dissimilar weld joint showed significantly higher tensile strength (590 MPa) than the HEA (327 MPa), making it suitable for structural applications.