Effect of rolling paths and pass reductions on the microstructure and texture evolutions of AZ31 sheet with an initial asymmetrical texture distribution

The asymmetrical planar mechanical behaviors of an extruded AZ31 sheet possessing bimodal texture distribution (a strong c-axis parallel to normal direction (ND) texture component accompanied with a sub-strong tilted c-axis parallel to transverse direction (TD) texture component) were investigated. Rolling process was carried on such an asymmetrically textured sheet to regulate the microstructure and texture, and thus to try to modify the poor room temperature mechanical properties. The results indicated that the plastic deformation mechanism activated in the c-axis parallel to TD textured grains during rolling was sensitive to the rolling paths. When the rolling direction was perpendicular to the tilted direction of the texture component, prismatic <a> slip and extension twinning would be activated in the c-axis parallel to TD oriented matrix, and their activities readily varied with the pass reduction. Whereas when the rolling direction was parallel to the tilted direction of the texture component, only extension twinning based on consuming the tilted texture component was permissible. As a result, the microstructure, texture, rollability and the final modified mechanical properties of the sheet were strongly dependent on the rolling paths, and their evolutions during various rolling processes were investigated in detail. This study could give instructional meaning on property modification of Mg alloy sheets with similar asymmetrical texture distribution. (C) 2019 Elsevier B.V. All rights reserved.