Self-organization behavior of defective structures as a mechanism of plastic strain localization under dynamic loading

The phenomenon of plastic strain localization in alloys under dynamic loading was experimentally studied on a Hopkinson–Kolsky bar and during target penetration tests. The temperature fields generated during deformation were studied in situ using a CEDIP Silver 450M high-speed infrared camera with the aim to identify the characteristic stages of localized shear. The temperature field distribution obtained at different time allowed us to trace the evolution of plastic strain localization. Microstructural analysis of the post-test samples was carried out using an optical interferometer-profilometer and electron microscopes. The structural analysis provided evidence for the correlated behavior of the ensemble of defects, which can be classified as a structural transition responsible for the strain localization. The results of experimental studies, the study of the deformed sample structure, as well as the data of numerical simulation made with consideration for the evolution of microdefects in the material, suggest that one of the mechanisms of plastic strain localization in alloys under high-speed loading is caused by jump-wise processes in the defective structure of materials.