Localized Plasticity Autowaves Evolution in Aluminium

The kinetics of plastic flow localization foci in polycrystalline Al is investigated at room temperature via double-exposure speckle photography. Plastic flow instability in the form of periodically changing spatiotemporal local deformation distribution is detected at parabolic hardening and pre-failure stages. The variation in autowave length and local elongation coefficient is found with the increase of total deformation. The evolution of the plastic flow at the final stage as an unstable cycle is discussed in the framework of the autowave plasticity model.