Modeling of the dynamic recrystallization behavior of Csf/AZ91D magnesium matrix composites during hot compression process

The deformation and microstructure evolution behavior of 15 vol% short carbon fiber reinforced AZ91D composites (Csf/AZ91D) were investigated by hot compression test. An obvious dynamic recrystallization (DRX) was found in the matrix alloy, and the recrystallized grains around the fibers were finer than those in the alloy. The average grain size and volume fraction of the recrystallized grain increases with the increase of deformation temperature or the decrease of strain rate. The volume fraction of the recrystallized grain increases with increasing strain in a rapid-slow manner. By regression analysis on these results, a constitutive model was developed for the first time in attempt to quantitatively evaluate the effect of temperature, strain and strain rate on the DRX behaviors. The calculated average grain size and volume fraction of the recrystallized grains are in good agreement with the experimental ones, thereby validating the accuracy of the developed model.