Influencing Factors of High-Pressure Discharge Nanothermite Composites Based on Al/Bi2O3

Abstract

To optimize the reactant synthesis and improve the pressure property of Al/Bi2O3, the influencing factors in the dynamic pressure discharge of nanothermite reactions are investigated, including the oxide type, Bi2O3 particle size, and fuel-to-oxidant mole ratio. All samples are prepared by the ultrasonic mixing method. The synthesized Al/Bi2O3 composites are characterized by X-ray diffraction analysis and scanning electron microscopy. By using a closed bomb, the pressure discharge characteristics, including the peak pressure, ignition delay time, and pressurization rate, are obtained. Among the as-prepared nanothermites Al/CuO, Al/Fe2O3, and Al/Bi2O3, the latter shows the best pressure discharge performance. For the Al (100 nm)/Bi2O3 (47 nm) composite with an optimal stoichiometric ratio, the maximum peak pressure, the pressurization rate, and the shortest ignition delay time are 4559 kPa, 11.398 GPa/s, and 27.20 ms respectively. The results indicate that the nano-Bi2O3 particle size also produces a significant effect on the pressure output.