Effect of Nb element content on microstructure and properties of FeAlCuCrNiNb_x high entropy alloy

In order to study effect of Nb element content on microstructure and properties of FeAlCuCrNiNb_x high-entropy alloy,FeAlCuCrNiNb_x high-entropy alloy was prepared by flux-cored wire surfacing method,while hardness,microstructure and phase composition of the weld were analyzed. The results showed that for FeAlNiNb_xCuCr series high entropy alloys,addition of Nb element had a certain positive effect on hardness of the alloy. When Nb molar ratio was 0. 8,hardness of the surfacing layer was the highest. The average hardness was 49. 53 HRC and the smallest wear extent was 0. 28 g. With the addition of Nb element,grain size of the high-entropy alloy first decreased and then increased. When Nb molar ratio was 0. 6,the FeAlNiNb_xCuCr high-entropy alloy had the smallest grain size and the least precipitate. When Nb molar ratio continued to increase,a large amount of high hardness precipitates appeared in microstructure of the alloy.