Evolution of Microstructure, Mechanical Properties, and Deformation Behavior of 1561 Alloy with Trace Er

In this paper, the effects of Er element on the microstructure, mechanical properties, texture and deformation properties of 1561 alloy were characterized by optical microscopy, scanning electron microscopy, mechanical properties testing and first-principles calculation. The results reveal that the addition of 0.12%Er reduces the grain size of as-cast alloy by 23% compared with that 295 mu m without Er. The tensile strength and yield strength of cold-rolled alloy with 0.12%Er are elevated by 3.8 and 4.0%, respectively. Al3Er can act as heterogeneous nucleation points, and its uniformly distributed within the grain can effectively impede the propagation of movable dislocations during deformation and recrystallization, which can increase the recrystallization temperature and uniformly dispersing deformation. However, the Al3Er phase exhibits brittleness, which will reduce the toughness of the alloy. For the PLC effect, the alloy containing Er has higher stress drop sigma and reloading time t. The increase in strain rate can distinctly reduce sigma and t. Therefore, conducting an adjustment of the processing rate of Al-Mg alloy appropriately in production is beneficial to the uniform deformation of the workpiece.