Effect of laser remelting on microstructure and mechanical property of AlCoCuFeNi high entropy alloy fabricated by laser additive manufacturing

An approach of laser remelting (LR) during laser melting deposition (LMD) process was applied to improve the forming quality and mechanical properties of the AlCoCuFeNi high entropy alloys (HEAs). In particular, the effect of laser remelting on the surface morphology, phase, microstructure and hardness of the parts were investigated using LSCM, SEM, XRD and Vickers microhardness tester. The results show that both LMD and LMD+LR samples dominantly consisted of a body-centered-cubic (BCC) and face-centered cubic (FCC) solid solution phases. There are many splash particles on the surface of the LMD part, which is attributed to the serious balling effect. The analysis shows that the LR process can improve the surface quality and microhardness of the LMD HEA samples due to the elimination of balling defects (microcracks and porosity).