The room temperature elongation of magnesium is a key variable for its large-scale application in the civil field. Experimental research shows that the addition of appropriate alloying elements can promote non-base surface slip in magnesium or weaken the texture, thereby enhancing the plasticity of the material. However, the contribution of these two effects to plasticity is lack of quantitative research.
Recently, Professor Zeng Xiaoqin and Professor Wang Leyun of Shanghai Jiaotong University in China and others studied the influence of rare earth element Nd and non-rare earth element Ca on magnesium tensile behavior. According to the initial texture of the material, a virtual material structure is established, and through the Visco-Plastic Self Consistent Modeling model, an accurate simulation of the material's tensile curve and texture evolution is achieved. The model gives the contribution of each slip system to the total dislocation density during deformation of each material. The simulation results show that the high plasticity of the Mg-Ca alloy is mainly due to the wide opening of the cylindrical surface slip, while the base surface sliding is still dominant in the Mg-Nd alloy, and the high plasticity is due to the weakening of the texture. This work provides theoretical guidance for the precise design of magnesium alloy components.
Alloying elements can drastically alter the deformation behavior of Mg. In the present work, Visco-Plastic Self-Consistent (VPSC) modeling was employed to investigate the effect of alloying elements on Mg's tensile behavior, in particular the relative activity of different slip and twinning modes. Mg-0.47wt.% Ca, Mg-2wt.% Nd, and AZ31 extruded alloys were deformed by micro-tensile tests in a scanning electron microscope (SEM). Texture and grain size measured by electron backscatter diffraction (EBSD) were used as the input for VPSC. After parameter optimization, the VPSC model successfully reproduced the stress-strain curve of each alloy. Simulation results indicate that the slip/twinning activity in the three alloys are different. Mg-0.47wt.% Ca shows strong extrusion texture, and prismatic slip was quite active during its tensile deformation. In contrast, Mg-2wt.% Nd shows weak extrusion texture, and basal slip was dominant. This alloy also developed more twinning activity than the o ther two alloys. AZ31 shows strong extrusion texture similar as Mg-0.47wt.% Ca, but prismatic slip was less active in it. The slip/twinning activity revealed by the VPSC model can explain the difference in the tensile behavior of the three alloys .