In this work, mechanical properties, the tensile anisotropy, and deformation mechanisms during tensile testing of rolled Mg-6.3Gd-3Li-2Zn-0.5Al alloys (R2 and R4) were analyzed with Visco-Plastic Self-Consistent (VPSC) model and material characterization techniques. The results showed that the mechanical properties of the rolled Mg-Gd-Li alloy displayed considerable anisotropy, with highest yield strength and tensile strength along the rolling direction (RD) measured at 272.3 MPa and 294.5 MPa, respectively. Conversely, the yield and tensile strength in the transverse direction (TD) were merely 214.7 MPa and 253.1 MPa, respectively. Furthermore, the anisotropy increased with the deformation. The VPSC models for rolled Mg-Gd-Li alloy in tensile deformation were constructed, respectively, by adjusting the hardening parameters. Pyramidal <c + a> slip, which dominated the deformation mechanisms of Mg-Gd-Li alloy, was calculated via VPSC model and observed in electron backscatter diffraction (EBSD) data. The stress-strain curves and pole figures generated from the VPSC model exhibited excellent agreement with experimental results. For the rolled Mg-Gd-Li alloy, the activation levels of basal <a> slip along different tensile directions were the main cause of the anisotropy in yield strength. On the other hand, the activation levels of (10–12) twinning during deformation in various tensile orientations were primarily responsible for the anisotropy in tensile strength.

The tension-compression asymmetry presents notable challenges for the application of magnesium alloys in many fields. In this study, the solid-solution treated Mg-8.5Gd-4.5Y-0.8Zn-0.4Zr alloy’s tension-compression asymmetry was examined using optical microscope (OM), x-ray diffraction (XRD), viscoplastic self-consistent (VPSC) modeling, and electron backscatter diffraction (EBSD). The VPSC hardening parameters were significantly adjusted based on the Schmid factor of deformation modes in rare earth magnesium (Mg-RE) alloy, which came from the EBSD data. Excellent agreement was found between the modified VPSC model’s calculation results, especially the stress-strain curves and pole figures. The alloy exhibited good strength with a negligible tension-compression asymmetry and an impressive 0.98 ratio of compressive yield strength to tensile yield strength (CYS/TYS). The main cause could be attributed to the unusual texture of (11-20) <0001> in alloy, which eliminated the imbalance in tension and compression deformation by having a negative effect on the activation of {10-12} twinning in tensile and a positive effect in compressive deformation. The activation level of {10-12} twinning was 0.37 and 0.40 calculated by VPSC model, in the plastic deformation of tension and compression, respectively; in the tensile and compression samples, the EBSD data indicated that approximately 31.9% and 31.1% (area proportion) of the grains were deformed with twins, respectively. Both tension and compression deformation showed the {10-12} twinning in the early stage of deformation, which transformed to {11-22} twinning in the later stage. The considerable activation of pyramidal <c+a> during the later stages of deformation endowed the alloy with good ductility.