The development of the aluminum sulfide synthesis reaction on explosive loading of a cylindrical ampoule

Abstract

In the scientific literature, much attention is paid to investigation of phase transitions on explosive load� ing, in particular, solidphase chemical transforma� tions under the action of shock waves. However, such transformations are studied mostly experimentally (1, 2), and their mathematical models are virtually unavailable. It is natural because chemical transfor� mations are difficult to study in the course of explosive loading and reliable data on the dynamics of these phenomena are not always easy to obtain from experi� mental results. Meanwhile, novel promising materials are more and more often produced and used in fast processes at high strain rates, pressures, and temperatures. These processes are accompanied by structural changes and sometimes chemical reactions. The currently widely used explosive technologies in metal working are most developed in forming, welding, cutting, hardening, and sealing, and many of these technologies have already been commercialized. At the same time, the effect of shock waves on solidphase reactions is still insufficiently studied and, by the present time, has not yet reached a technology level because of the lack of experimental data and also mathematical models that could take into account both the coupling of mechan� ical and physicochemical processes, including their combined action, and the effect of each factor. The purpose of this work was to experimentally and numerically study the dynamics of development of aluminum sulfide synthesis on explosive loading of a cylindrical ampoule on the basis of a phenomenologi� cal model of chemical transformations. In this work, we proposed a new approach to numerical analysis of solidphase synthesis processes on explosive and shockwave loading on the basis of a developed mathematical model of a multicomponent medium. The time dependence of the pressure of the explosion products was described based on qualitative and quantitative agreement of the results of experi� mentally and theoretically determining the parame� ters of explosive loading of a cylindrical ampoule. The conditions were found for the transition from partial to complete conversion in the synthesis reaction in the shock front on reflection of the shock wave from the bottom cap of the ampoule. It was experimentally and theoretically established that, once the reaction in the shock wave is fully completed, the ampoule is broken down because of the formation of a gas phase and an increase in pressure, with the breakdown being initi� ated in the bottom part of the ampoule.