Microstructure and properties of AlCoCrFeNiNbx (x = 0, 0.1 and 0.5) high-entropy alloys enhanced by laser remelting.

In order to improve the properties of AlCoCrFeNiNb x (x = 0, 0.1, and 0.5) high-entropy alloys (HEAs), the microstructure of the AlCoCrFeNiNb x is regulated by laser remelting (LR). By testing the microstructure and properties of alloys before and after LR treatment，the results indicate that the original AlCoCrFeNiNb x alloys have typical dendritic morphology, and the addition of the Nb element promoted the formation of Laves phase. The grains were significantly refined after LR treatment, and the dense remelting layers with thicknesses ranging from 1200 μm to 1650 μm were formed on the surface of the alloys. In addition, the hardness and wear resistance of the alloys were improved with the increase of Nb content and LR treatment due to the combined effect of fine grain strengthening, solid solution strengthening, and the second phase strengthening. At the same time, the corrosion resistance of the alloys before and after LR treatment in 3.5 wt% NaCl solution was significantly improved by the stable Nb 2 O 5 passivation film for Nb 0 and Nb 1 alloys. • LR treatment was conducted on the surface of as-cast AlCoCrFeNiNb x (x = 0.1,0.5 and 1) high entropy alloys. • AlCoCrFeNiNb x alloys have typical dendritic morphology, and the addition of the Nb element promoted the formation of Laves phase. • The grains were significantly refined after LR treatment, and the dense remelting layers with thicknesses ranging from 1200 μm to 1650 μm were formed on the surface of the alloys. • The hardness and wear resistance of the alloys were improved with the increase of Nb content and LR treatment due to the combined effect of fine grain strengthening, solid solution strengthening, and the second phase strengthening. • The corrosion resistance of the alloys before and after LR treatment in 3.5 wt% NaCl solution was significantly improved by the stable Nb 2 O 5 passivation film for Nb 0 and Nb 1 alloys. [ABSTRACT FROM AUTHOR]