Effect of Neodymium on Microstructure and Mechanical Properties of Mg-Sb Alloy

The effects of Nd on the microstructure and mechanical properties of Mg-Sb3 alloy were studied with the 0 ∼ 0.15% addition content. The addition of Nd makes the grain of Mg-Sb3 alloy obviously refined, where the grain size decreases from 100 ∼ 200 μm to 0.2 ∼ 10 μm. And the typical dendrite characteristic turns into the equiaxed grain microstructure with the addition of 0.05% ∼ 0.1% Nd. The reason for grain refinement is from the supercooling theory. The mechanical properties tested indicate that the tensile strength and especially elongation of the alloys are improved with the addition of Nd and their maximum enhancing rates based on the Nd-free Mg-Sb3 alloy are 20% and 10% at 0.1% Nd, respectively. The main reason is attributed to the grain refinement by Nd. The tensile strength and especially elongation decline when Nd addition is over 0.1%, owing to the number and size increase of the needle-shaped phases on the grain boundaries with the Nd addition increasing.