Issue 24

Andrey E. Buzyurkin et alii, Frattura ed Integrità Strutturale, 24 (2013) 102-111 ; DOI: 10.3221/IGF-ESIS.24.11 102 Special Issue: Russian Fracture Mechanics School Study of the conditions of fracture at explosive compaction of powders Andrey E. Buzyurkin, Evgeny I. Kraus Khristianovich Institute of Theoretical and Applied Mechanics of Siberian Branch of RAS, 4/1 Instituskaya str., Novosibirsk, 630090, Russia buzjura@itam.nsc.ru , kraus@itam.nsc.ru Yaroslav L. Lukyanov Lavrentyev Institute of Hydrodynamics of Siberian Branch of RAS, 15 Lavrentyev pr., Novosibirsk, 630090, Russia lukyanov@hydro.nsc.ru A BSTRACT . Joint theoretical and experimental investigations have allowed to realize an approach with use of mathematical and physical modeling of processes of a shock wave loading of powder materials. In order to gain a better insight into the effect of loading conditions and, in particular, to study the effect of detonation velocity, explosive thickness, and explosion pressure on the properties of the final sample, we numerically solved the problem about powder compaction in the axisymmetric case. The performed analysis shows that an increase in the decay time of the pressure applied to the sample due to an increase of the explosive thickness or the external loading causes no shrinkage of the destructed region at a fixed propagation velocity of the detonation wave. Simultaneously, a decrease in the propagation velocity of the detonation wave results in an appreciable shrinkage of this region. K EYWORDS . Shock waves; Fracture; Powder. I NTRODUCTION ethods of explosive loading of powder materials in conservation ampoules are applied in order to obtain new materials including composite ones with the unique physical and mechanical properties. In addition, these methods can be used to study phase transitions occurring in materials at high pressures and temperatures taking place behind shock waves, as well as for the synthesis of metastable phases. In recent decades, significant development has been achieved in such a scientific and technical branch of materials science as powder metallurgy. This term is currently understood a whole complex of problems connected with the design of materials and products from metal and nonmetal powders. Interest in these problems is quite understandable since the opportunity to create new classes of materials with unique and controllable properties which can not be obtained by ordinary metallurgy methods has arisen. A special place in the powder metallurgy is occupied by explosive compaction of powder materials. It is easy to explain the strong interest in the explosive compaction. It consists in the fact that virtually all the methods of composite materials' production from powder mixtures lead to a change in initial material properties due to high temperatures and relatively long duration of the process. M