The character of plastic strain localization in a recrystallized Zr-2.5% Nb alloy

We have studied the deformation behavior of a recrystallized zirconium-niobium (Zr-2.5% Nb) binary alloy (commercial É125 grade) on a macroscopic level. The evolution of the spatiotemporal distributions of local strain in all stages of the work hardening process has been analyzed. It is established that the stage of prefracture involves the formation of localized plastic flow foci with various levels of strain accumulation. The focus with maximum strain amplitude is almost immobile and indicates a future site of fracture. The other zones of strain localization move with velocities that increase with the distance from the fracture focus. An analysis of the kinetics of strain localization foci allows the sample lifetime to be evaluated and the fracture site coordinates to be predicted.