Dissimilar laser welding of an as-rolled CoCrFeMnNi high entropy alloy to Inconel 718 superalloy

In this work, dissimilar laser welding between an as-rolled CoCrFeMnNi high entropy alloy (HEA) and Inconel718 Ni-base superalloy was successfully performed. Defect-free joints with a tensile strength of 822 MPa and afracture strain of 7.1 % were obtained. The microstructural analysis was conducted using scanning electronmicroscopy (SEM), electron backscattered diffraction (EBSD), energy-dispersive X-ray spectroscopy (EDS) andhigh energy synchrotron X-ray diffraction (SXRD), complemented by thermodynamic calculations using theCalPhaD methodology. Mechanical assessment of the joints was conducted via microhardness mapping andtensile testing, allowing to unveil processing-microstructure-properties relationships. Although the precipitationof the Laves phase was identified within the fusion zone, our results reveal the excellent dissimilar weldabilitybetween the two alloys, allowing the deployment of this dissimilar material pair for structural applications.