Spatially focused microwave ignition of metallized energetic materials
Dylan J. Kline, Miles C. Rehwoldt, Charles J. Turner, Prithwish Biswas, George W. Mulholland, Shannon M. McDonnell, Michael R. Zachariah
Abstract
This study investigates the ability to locally ignite metallized propellants via microwave absorption. Metallized energetic composite films incorporating high mass loadings of aluminum and titanium nanoparticle fuels within a polyvinylidene fluoride (PVDF) polymer matrix were constructed by direct-write additive manufacturing (3D printing). Simulations of power absorption for both Ti and Al nanoparticles reveal that the passivating shell composition likely plays a significant role in the observed ignition phenomenon. Various architectures of interest were constructed for predictable microwave ignition and propellant propagation. It was found that, although aluminum nanoparticles and composites do not ignite via exposure to microwaves, titanium nanoparticles can be used as efficient reactive microwave susceptors enabling a localized ignition source. This approach enables various architectures of previously studied high energy Al/PVDF systems to be fabricated and outfitted with a microwave-sensitive titanium composite in strategic locations as a means of remote ignition for aluminum systems.