Dissimilar gas tungsten arc welding of an AlCoCrFeNi high entropy alloy to 316 L stainless steel

High entropy alloys (HEAs) are unique and novel materials with remarkable properties that render themcompetitive for developing key engineering applications within modern engineering sectors. In the present study,a AlCoCrFeNi HEA was gas tungsten arc welded to 316 L stainless steel, with the aim of assessing the compatibilityin terms of microstructure and mechanical performance. These dissimilar joints was obtained with a torchspeed of 3.5 mm/s and a current intensity of 90 A under a protective Argon atmosphere. Subsequently, athorough evaluation of the relationship between processing parameters, microstructure and properties wasperformed via optical and electron microscopy, atom probe tomography, synchrotron X-ray diffraction, microhardnessmapping and tensile testing. The results reveal that the AlCoCrFeNi HEA can be successfully weldedwith 316 L stainless steel, producing a high-quality and reliable joint, where a gradual microstructural variationis observed across the interface. A good balance of a high tensile strength of ≈568 MPa and fracture strain of≈11.7% was obtained, with fracture occurring in the fusion zone, highlighting the potential of these dissimilarjoints for critical structural applications.