On the Mechanical Behaviors of Extruded AZ61A Magnesium Alloy Tube Under Cyclic Torsion

Load-bearing structural components of magnesium alloys are frequently subjected to cyclic shear. Therefore, understanding the mechanical behavior of magnesium (Mg) alloys under cyclic shear is essential for the design, fabrication, and service of the end products. In this work, the cyclic torsion test of extruded AZ61A Mg alloy tube is conducted. In parallel, the elastic viscoplastic self-consistent model with the twinning and detwinning scheme, in conjunction with a torsion-specific finite element approach, is employed to model cyclic torsion. The mechanical responses under cyclic torsion are well captured by the model. The characteristic cyclic behavior of the extruded AZ61A tube is governed by the alternating twinning and detwinning In addition, the Swift effect, the twin volume fraction, and relative activities of deformation mechanisms under cyclic torsion are also revealed.