Microstructure and Mechanical Property Evolution of Rare Earth-Containing Al-Mg Alloy During Cold Drawing

Al-3.0Mg-xRE (mass fraction/%, x=0, 0.12, 0.31, RE=La+Ce) alloys containing different-content rare earth were smelted. The evolution of the microstructure, hardness and tensile properties of the alloys were investigated in cold drawing. The results show that during the cold drawing, the grains of the test alloys were elongated; the second phase particles were also elongated and fragmented to small particles, and then gradually aligned on grain boundaries and dendrite boundaries in linearity; the intensity of Copper 112〈111〉 deforming texture increased. With increasing deformation amount, the strength of the alloys increased linearly, the plasticity decreased and the hardness increased. Proper rare earth addition (0.12%) could improve the microstructure and the mechanical properties of the alloy. However, excessive rare earth addition (0.31%) increased the number and size of the second phases in the alloy, thereby reducing the mechanical properties of the alloy. After cold drawing, the Al-3.0Mg-0.12RE alloy had the smallest and the least second phases, the highest deforming texture intensity and the best mechanical properties.