On the Relationship between the Spatial Characteristics of Multi-Scale Plastic Deformation Localization Processes in Aluminum

The paper investigates patterns of plastic flow localization during uniaxial tension of polycrystalline aluminum with stable loading curves ensured by specific micromechanisms of plastic flow within the temperature range of 170<T<350 K. The study of macroscopic deformation fields is conducted with the speckle photography technique. It allows identifying evolution patterns of spatio-temporal distributions of the distortion tensor components during tensile testing of flat samples. The distributions of local deformations take the form of a system of equidistantly located stationary foci of localized plastic deformation (stationary dissipative structure) at the stages of parabolic strain hardening. The spatial period (which is the distance between the maxima of local elongations along the extension axis, the autowave length) is the geometric characteristic of such structures. Temperature dependence is revealed for the spatial period distributions of local elongations and dislocation substructures sizes for the parabolic strain hardening stages in Al.