An advanced manufacturing process for producing metal-fueled pyrotechnic munitions has been developed using the Sequential Particle Addition (SPA) methodology in the fluidized bed processor. During this process, both the large metal fuel particles and small oxidizer particles are coated with low viscosity UV curable monomers or oligomers in a desirable protocol, followed by curing the UV curable compositions and clustering into solids by UV irradiation. In this study the "host" particles, ～350 μm diameter magnesium or its inert stimulant, were first pre-coated with UV composition. Next the small "guest" particles, ～30 μm sodium nitrate or its inert stimulant, were added through the special designed side powder feeder. It was found that during the mixing and fluidization process, the small guest particles were being coated as a result of UV reactive composition being transferred from the large coated particles to the small particles, which lead to the formation of ordered mixtures in a self-assembly fashion. The final product was composed of the core section containing individual large metal fuel particle, and a shell section consisting of a designable amount of small oxidizer particles. Once cured, the UV reactive composition, which was initially used as the coating material, formed secure bridges between the large and small particles, thereby stabilizing the final structure for subsequent handling and processing. This fluidized bed UV coating technology is solvent-free, environmental benign, and enables the scalable production of pyrotechnic compositions with moisture sensitive metallic fuels and/or oxidizers at controllable stoichiometric ratios. The final products made from this fluidized bed UV coating process possess exceptional microscopic compositional uniformity and are free of unbound particles.
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