Laser beam welding of AlCoCrFeNi2.1 eutectic high-entropy alloy

To determine the potential of an AlCoCrFeNi2.1 eutectic high entropy alloy (EHEA) as a structural material, its laser beam welding (LBW) performance was evaluated, and the microstructure and mechanical properties of weld joint were studied. A fully penetrated, defect-free joint was obtained, in which the fusion zone (FZ) exhibited a eutectic lamellar microstructure containing FCC(L12)/BCC(B2) solid solution phases. The FZ contained refined columnar grains, which grown with the preferential 〈111〉 orientation induced by the rapid cooling during LBW. The tensile strength of the FZ was superior than that of the base metal (BM), which was attributed to grain refinement and higher dislocation density. LBW is a suitable process for joining AlCoCrFeNi2.1 EHEAs.