DSC analysis on AA2219 plates processed by cryorolling and coldrolling

Phase transformation in AA2219, is essential in order to understand its strength enhancement especially through precipitation. In this study, Differential scanning calorimetry studies were conducted at different heating rates on AA2219 plates rolled at cryogenic and cold rolling to characterize the reactions that take place in the rolled material. The precipitates evolved at different temperatures were identified and energy stored during the rolling process was also calculated. Cryorolled material showed higher stored energy and therefore enhanced precipitation kinetics compared to the cold rolled sample. The activation energy for precipitation and dislocation density under different conditions were determined from Kissinger and Williamson Hall plots respectively. The lower activation energy for the precipitate formation and the excess dislocation density exhibited by the cryorolled samples are identified as the cause for their superior precipitation kinetics.