A temperature-dependent crystal plasticity model for predicting cyclic loading behaviors of a magnesium alloy

In this work, a crystal plasticity finite element (CPFE) model to predict cyclic loading behaviors at elevated temperatures of a wrought magnesium alloy, i.e., AZ31B sheet, is proposed. The temperature-dependent mechanical behavior is systematically modeled by modifying the strain-hardening model. The twinning-detwinning, a key deformation mechanism that occurs during the cyclic loadings in the magnesium sheet, is also modeled based on the well-known predominant twinning reorientation (PTR) scheme. Furthermore, to better predict the detwinning behavior, a concept of residual twin is also introduced and employed in the PTR scheme. The modified strain-hardening and enhanced-PTR model considering the twinning-detwinning are implemented in the CPFE framework. Using the developed model, mechanical responses of the AZ31B sheet under cyclic loading conditions at various testing temperatures up to 200°C are predicted and compared with the experimental data, and the prediction results are promising.