Relationship between textures and deformation modes in Mg-3Al-1Zn alloy during uniaxial tension

摘要

The effects of initial texture on the flow behavior, microstructure and texture evolution of Mg-3Al-1Zn alloy hot rolled plate with a strong basal texture during tension at room temperature have been investigated by experiments and simulations. Three kinds of specimens were cut from this plate with their tensile directions aligned 0 degrees,45 degrees, and 90 degrees to the normal direction (ND), and they were referred as 0ND, 45ND and 90ND specimens, respectively. A crystal plasticity model was developed to demonstrate the relationship between textures and deformation modes. The results show that the general features of flow curves and texture evolutions of AZ31 alloy during tension can be well explained by the relative activities of deformation modes, which exhibit a pronounced orientation dependence on both the starting and current textures. The obvious yielding behaviors in 0ND and 45ND specimens are induced by the initial activity of {10-12} twinning, and the strain hardening behavior is related to the activities of {10-12} twinning, basal slip and prismatic slip. Due to the existence of {10-11} twinning at low strain, the elongation to rupture of 90ND specimen is much lower than those the elongation of 0ND and 45ND specimens. Although prismatic slip activity depends on the initial texture, its activities always increases during tension, affecting the flow curves, microstructure and texture evolutions. The high prismatic slip activities in 0ND and 90ND specimens result in a strong {10-10} prismatic texture, while the activity of pyramidal slip is always negligible in all specimens and insensitive to the initial texture during tension. (C) 2015 Elsevier Inc. All rights reserved.