Hot workability and dynamic recrystallization behavior of a spray formed 7055 aluminum alloy

Abstract

In this work, the hot workability of a spray formed 7055 aluminum alloy was successfully investigated through advanced Gleeble thermo-mechanical simulation technology, and the EBSD technology was adopted to analyze the evolution of deformation microstructure comprehensively. From the results, the occurrence of the adiabatic heating phenomenon is confirmed, and an abnormal stress drop caused by which is then corrected by the extrapolation method. Moreover, it is noteworthy that with rising deformation parameters (including deformation temperature T from 350 °C to 450 °C, strain rate ε̇ from 1 s−1 to 20 s−1 and true strain ε from 0.1 to 0.8), the grains become finer, and the distributions of crystal orientation tend to be more homogeneous. Besides, it is found that both the Continuous Dynamic Recrystallization (CDRX) and Discontinuous Dynamic Recrystallization (DDRX) mechanisms coexist during hot deformation. Moreover, the increase of the three deformation parameters enlarges the misorientation angle inside the grains, which facilitates the DRX progress.