Modeling the effect of pre-straining on mechanical behavior of magnesium alloy sheet

Experimental observations indicate that pre-deformation can influence the mechanical properties of magnesium alloys. However, inconsistent or even contradictory conclusions have been drawn mainly due to the difficulty of isolating an individual influencing factor from those playing interactive roles in an experiment. Therefore, a systematical study in terms of crystal plasticity modeling is performed to evaluate the effect of pre-deformation (pre-rolling and pre-compression) in the current work. The subsequent tensile response of the magnesium alloy AZ31B sheet along the transverse direction and the rolling direction after pre-deformation is simulated. It is found that both pre-rolling and pre-compression can either enhance or deteriorate the mechanical properties of the AZ31B sheet. If annealing is applied, the pre-deformed microstructure is retained and the mechanical properties are generally enhanced. Pre-compression with ~ 3% strain and annealing are able to enhance the overall mechanical properties of a rolled Mg alloy sheet the most. Based on the modeling results, the properties of magnesium alloys can be affected differently with different pre-straining paths, different loading directions, with annealing or without. These findings help us understand the inconsistency in different experimental studies and also reveal the role of pre-deformation and the accompanying influencing factors on the properties of magnesium alloys.