Influence of annealing on recrystallization and mechanical properties of Zr702 alloy obtained by accumulative roll bonding

The influence of annealing time on the recrystallization evolution and mechanical behavior of Zr702 alloy obtained by accumulative roll bonding (ARB) has been investigated. Results show that the bonding degree of the ARB interface gradually improved with the increase of annealing time from 5 to 20 min, which is because the atoms can obtain relatively more diffusion driving force with the increase of annealing time. In addition, almost complete recrystallization (average size of about 3.98 μm) and excellent comprehensive mechanical properties can be obtained as the annealing time is set to 20 min, and the evolution path of the microstructure with annealing time can be described as: (I) high density stacking dislocations; (II) formation of subgrain boundaries; (III) reduction of dislocation density and formation of recrystallization; (IV) growth of recrystallized grains. In this study, with the increase of annealing time, the release of deformation storage energy and the increase of recrystallized dislocation-free grains are very helpful to improve the ductility.