Characterization of Laser Beam Welded Al<sub>0.5</sub>CoCrFeNi High-Entropy Alloy

Abstract

High-entropy alloys (HEA), a new generation alloy system offer superior mechanical properties with solid solution strengthening. AlxCoCrFeNi-HEA is one such system being received more attention because of its specific yield strength and ductility. In the present work, Al0.5CoCrFeNi-HEA was prepared by vacuum arc melting. The laser beam welding (LBW) was carried out on 1mm thick forged and homogenized HEA, with a beam power of 1.5 kW and at a traverse speed of 600 mm/min. The microstructural features of different regions of the weld were studied using scanning electron microscopy. The homogenized Al0.5CoCrFeNi-HEA have shown equiaxed grains of average size 60 μm. The weld metal showed a typical weld fusion zone microstructure with dendritic structure with a reduction in BCC phase due to minimal Al and Ni segregation ratio at interdendrites. Micro-chemical analysis with energy dispersive spectroscopy confirmed that there was no major segregation of elements in the weld fusion zone. The microhardness survey performed across the weld evidenced a reduction in hardness, as a consequence of significant reduction in Al-Ni rich hardening factor.