Grain-refining of wire arc additive manufactured aluminum alloy with Nb powder addition

Abstract Nb powder with an average diameter of 15 μ m was added to the molten pool during wire arc additive manufacturing of 5B06 aluminum alloy. The unmelted Nb with high melting point and the in-situ alloying of Al 3 Nb acted as heterogeneous nucleation core. The fine equiaxed grains with a diameter less than 50 μ m was achieved, and the texture intensity of which was obviously weakened. An improvement in both the ultimate tensile strength and elongation of the Nb added samples were observed, and the micro-hardness of which was also improved due to the refined grain structure.