(493b) A Materials Science-Based Approach for the Re-Development of COMP B

Materials science focuses on investigating the relationships that exist between materials processing, composition, structure, property and performance. In this work, we aim to re-develop Composition B (Comp B) using a materials science based approach. Comp B is traditionally produced by a melt-cast process in which a slurry of large RDX crystals dispersed in molten TNT is cast and allowed to solidify into a charge. It is a widely used formulation due to its relatively high performance and low cost. However, Comp B is a relatively shock sensitive formulation, most likely due to the structural defects such as large voids formed during the solidification process of TNT. To eliminate large voids that play a role of sensitizing the explosive, we prepared nanoenergetics-based Comp B (N-Comp B) by compacting a molding powder which was prepared by spray drying and consists of nanoscale RDX and TNT. Reduced shock sensitivity was observed from N-Comp B, however, the decrease seems to have been limited by the presence of a large number of voids. The addition of a small amount of polymeric binder during the spray drying process was found effective in further reducing the size of voids, and more importantly, the number density of voids. This leads to a significant shock sensitivity reduction compared to melt-cast Comp B. This work continues to demonstrate the versatility of the spray drying-based materials processing method for nanoenergetics-based explosive formulations. Furthermore, it suggests that a materials science-based approach can facilitate the re-development of existing formulations or the development of new formulations to fulfill the sensitivity and performance requirements of the next generation explosives.