Wire-arc additive manufactured Al-Cu alloy: microstructure, mechanical properties and their anisotropy

The microstructure, mechanical properties and their anisotropies of wire-arc additive manufactured Al-Cu alloy at two different printing speeds were investigated, and post heat treatment is optimised. The results show that the grains are finer and the fraction of primary second phase is lower in the alloy prepared at the faster printing speed. The aging hardening response of the solution-treated sample is significantly faster than that of the direct-aging sample, and the peak hardness is higher. The mechanical properties of the as-deposited and T6-treated alloy both show anisotropy, and the latter one is more significant. The anisotropies are mainly attributed to the high porosity in inter-layer of the samples, and these pores are more significant for the T6-treated samples.