高 球 形 度 核 壳 结 构 超 级 铝 热 剂 的 制 备 及 点 火 性 能

In order to obtain super thermite with spherical core-shell structure for 3D printing of energetic materials，Al_2#@CuO and Al_2#@Bi₂O₃ super thermites possessing highly spherical core-shell structure were prepared by spray granulation method for directly coating solid particles. The influence of construction parameters（particle size ratio and solid content）on particle size of super thermite was studied by using NanoMeasure statistical software. The spherical core-shell structure was characterized by scanning electron microscopy and X-ray diffraction. The flowability of super thermite was characterized using the angle of repose method. The ignition characteristics were observed using high-speed cameras. The results show that two types of super thermite possessing highly spherical core-shell structure were prepared using construction parameters of solid content 25%，2# alumi- num powder，and nano metal oxide（CuO，Bi₂O₃）particle size. The structure was an ideal spherical core-shell structure，with an average particle size of about 40 μm. The average thickness of the shell is 7.79 μm（Al_2#@CuO-25%），10.47 μm（Al_2#@Bi₂O₃- 25%）. Compared with the mechanically mixed sample，the flowability of super thermite with spherical core-shell structure dis- plays a great improvement. The angle of repose of Al/CuO system reduces from 48.8° to 22.9° ，and the angle of repose of Al/Bi₂O₃ system decreases from 37.3° to 16.6°. The combustion time of Al_2#@CuO super thermite with spherical core-shell struc- ture increases from 100 ms to about 0.9 s，indicating that microstructure variation has an impact on its combustion characteris- tics.