Abstract:A polycrystal plasticity model was developed to analyze the room-temperature deformation behaviors of Mg-3Al-1Zn alloy (AZ31). The uniaxial tension and compression tests at room temperature were conducted using cast and extruded AZ31 rods with different textures and combined with the proposed model to reveal the deformation mechanisms. It is shown that, different flow curves of two specimens under tension and compression tests can be simulated by this model. The flow curves of AZ31 extrusions exhibit different shapes for tension and compression due to different activities of tensile twinning and pyramidal ác+a？ slip. The metallographic and TEM observations showed the equal twinning activities at the initial stage in tension and compression tests and the occurrence of pyramidal ác+a？ slip in compression of as-cast Mg-3Al-1Zn alloy with increasing the strain, which is consistent with the simulated results by the proposed model.

Key words: Mg alloy; deformation mechanism; polycrystal plasticity model; texture