The shock-induced chemical reaction behaviour of Al/Ni composites by cold rolling and powder compaction

Abstract

Al/Ni composites are typical structural energetic materials, which have dual functions of structural and energetic characteristics. In order to investigate the influence of manufacturing methods on shock-induced chemical reaction (SICR) behaviour of Al/Ni composites, Al/Ni multi-layered composites with 3–5 cold-rolling passes and Al/Ni powder composites were obtained. Microstructural observation using scanning electron microscopy (SEM) and two-step impact initiation experiments were performed on the four Al/Ni composites. Furthermore, mesoscale simulations, through importing SEM images into the finite element analysis to reflect the real microstructures of the composites, were performed to analyse the particle deformation and temperature rise under shock compression conditions. The experimental results showed the distinct differences on the SICR characteristics among the four Al/Ni composites (i.e. by 3, 4 and 5 cold-rolling passes and powder compaction). The manufacturing methods provided the control of the particle sizes, particle distribution and the content of the interfacial intermetallics at scale of different microstructures, which ultimately affected the temperature distribution, as well as the contact between Al and Ni in Al/Ni composites under shock loading. As a result, the Al/Ni powder composites showed the highest energy release capacity among the four composites, while the energy release capability of Al/Ni multi-layered composites decreased with the growth of rolling passes.