Design, fabrication and mechanical properties of a novel Al-5Cu-6Gd-10Bi alloy potentially used for shielding both thermal neutron and γ-ray

In this work, a novel Al-5Cu-6Gd-10Bi alloy was designed based on Monte Carlo simulation and fabricated using ultrasound-assisted casting for potentially co-shielding thermal neutron and γ-ray. Theoretical simulation showed that the alloy exhibited potentially excellent shielding performance. A core-shell structured Bi@Gd₅Bi₃ phase, as well as Al₂Cu, were formed in the alloy. Hot-rolling promoted the fragmentation and more homogeneous distribution of large-sized Al₂Cu particles in the as-cast sample as well as the dispersive precipitation of fine secondary Al₂Cu particles, leading to the improvement of the mechanical properties of the alloy. Compared with the as-cast sample, the yield strength (YS), ultimate tensile strength (UTS), and elongation (El) of the as-rolled sample were increased by 47.8 %, 47.0 %, and 605.3 %, respectively, showing that the alloy had a desirable hot workability. The significant improvement of mechanical properties of as-rolled sample was attributed to the grain refinement strengthening and Orowan strengthening. The current lead-free alloy is anticipated to emerge as a promising material for shielding thermal neutron and γ-ray mixed radiation.