Effect of deformation temperature on the change in dislocation density during tensile deformation in industrial pure aluminum

An in-situ XRD measurement system using synchrotron radiation was developed to investigate the effect of deformation temperature on the change of dislocation density during deformation. In A1200 aluminum, the dislocation density hardly changed during plastic deformation at room temperature. On the other hand, it decreases with increasing strain as the deformation temperature increases. The stress at which dislocations begin to multiply did not change with increasing deformation temperature, but the dislocation density required for plastic deformation to proceed decreased significantly with increasing deformation temperature up to 573K. Analysis using the Kocks & Mecking model showed that the temperature dependence of the dislocation multiplication rate was small, but the dynamic restoration rate increased monotonically with increasing temperature. Therefore, as the deformation temperature increased, dislocation annihilation due to dynamic recovery or recrystallization became dominant over dislocation multiplication, and the dislocation density decreased during plastic deformation.