Effect of Nd addition on microstructures and heat-resisting properties of 2519 aluminum alloy

The effect of Nd on the mechanical properties and microstructures of 2519 aluminum alloy were investigated by means of hardness test, mechanical properties test, X-ray diffraction, OM, SEM and TEM. The results show that, with addition of Nd, the hardness and strength enhance. Nd can react with Al and Cu, and the intermetallic compound Al8Cu4Nd forms, which disperses along the grain boundaries. The mechanical properties at elevated temperature are improved because this dispersed compound prevents the deformation of matrix and movement of the grain boundaries at elevated temperature. The aging precipitates can be refined with appropriate addition of Nd, which increases the mechanical properties of the alloy. Adding 0.14% Nd increases the tensile strength about 15.4% at 300C and that at room temperature by 4.4%. With further addition of Nd, the mechanical properties at room and high temperature decrease.