Influence of structural factors on the strength properties of aluminum alloys under shock wave loading

The results of measurements of the strength characteristics - Hugoniot elastic limit and spall strength of aluminum and aluminum alloys in different structural states under shock wave loading are presented. Single-crystals and polycrystalline technical grade aluminum А1013 and aluminum alloys А2024, АА6063Т6, А1421, A7, А7075, А3003, A5083, АА1070 in the initial coarse-grained state and ultrafine-grained or nanocrystalline structural state were investigated. The refinement of the grain structure was carried out by different methods of severe plastic deformation such as Equal Chanel Angular Pressing, Dynamic Channel Angular Pressing, High-Pressure Torsion and Accumulative Roll-Bonding. The strength characteristics of shock-loaded samples in different structural states were obtained from the analysis of the evolution of the free surface velocity histories recorded by means of laser Doppler velocimeter VISAR. The strain rates before spall fracture of the samples were in the range of 104-105 s−1, the maximum pressure of shock compression did not exceed 7 GPa. The results of these studies clearly demonstrate the influence of structural factors on the resistance to high-rate deformation and dynamic fracture, and it is much less than under the static and quasi-static loading.