Regimes of interscale momentum exchange in shock deformed solids

Three regimes of interaction of shock wave and inner structure of solid are studied: (i) reversible interscale momentum exchange, (ii) irreversible interscale momentum exchange, and (iii) resonance regime. Theoretical analysis of the regimes is carried out by using a concept of the particle velocity distribution function and its statistical moments. As a test material for the experiments, D16 Al alloy is taken, firstly because of its initial heterogeneity and, secondly due to avalanche-like increasing of the heterogeneity in non-linear deformation process. Shock tests of D16 Al alloy within impact velocity range of 85(sic)450 m/s evidence that maximum dynamic strength is realized when two conditions are fulfilled simultaneously: (i) space period of polarized dislocation structure equals to width of shock front and (ii) local strain rate at the mesoscale equals to macroscopic strain rate. The resonance regime results in formation of dynamically recrystallized structures which are revealed with the metallography and X-ray analysis. (C) 2013 Elsevier Ltd. All rights reserved.