Temperature Dependence of Hall–Petch Parameters Using In Situ Diffraction Experiments in AZ31 Alloy

The temperature evolution of the Hall–Petch parameters for basal slip and twinning systems has been evaluated for the AZ31 alloy, using synchrotron radiation diffraction during compression tests from room temperature to 473 K. The AZ31 alloy was processed following two processing routes, casting and powder metallurgy, to obtain two different grain sizes with a similar strong fiber texture. Although macroscopic plasticity is controlled by tensile twinning, the stress for the activation of basal slip can also be calculated. At low temperatures, the grain size dependence of twinning is much higher than that for basal slip. However, basal slip prevails at 473 K, especially for the alloy processed through the powder metallurgy route, because of the low tendency for twinning deformation