(491b) Preparation and Characterization of Metal-Bound Hybrid Reactive Particles

This study is directed to establish the feasibility of preparing hybrid reactive materials with increased strength and energy density. The goal of this study is to produce reactive materials with coarse, fully dense, and mechanically strong particles, which, at the same time, are highly reactive. In order to achieve these characteristics, hybrid particles consisting of reactive nanocomposite filler and metallic binder were produced by mechanical milling. In a preliminary step, aluminum-rich nanocomposite thermite particles with CuO and MoO3 serving as oxidizers were prepared by Arrested Reactive Milling. These nanocomposite powders were embedded into Al matrix, also using mechanical milling with properly selected process parameters. The product hybrid material with particle sizes close to 1 mm was obtained. It consisted of aluminum matrix and micron-sized inclusions of the nanocomposite thermite material. Using the same technique, reference material was also prepared. It consisted of only aluminum, while the particle sizes and morphologies were the same as for the hybrid material. The effect of metal ? thermite composition and milling time on the hybrid particle size distribution was studied. The compositions and structures of the produced hybrid particles were characterized by X-ray Diffraction and Scanning Electron Microscope. Individual Al-bound hybrid material particles and reference aluminum particles of approximately the same size were ignited with a CO2 laser. It was observed that the ignition of hybrid particles containing nanocomposite material inclusions occurred faster than for the reference pure Al particles. The combustion of hybrid particles occurred with ejection of burning fragments and was completed sooner compared to the nearly steady and slow combustion of the similar size and morphology reference aluminum particles.