Study On Preparation, Characterization And Properties Of Al/Ni Nanoenergetic Composites

In this study, we have introduced a new way to prepare nanoenergetic material (nEM), and the embedded Al/Ni nEM was successfully developed on silicon substrate.Initially, Porous alumina membrane (PAM) has fabricated on the Ti/Si substrate by a two-step anodization in 0.3 M oxalic acid under a constant voltage of 40 V. The anodization was monitored by an I-t graph to investigate the process of the PAM forming. Also, we have studied the pore-widening step in 5 wt% H3PO4 and the influence of anodization time on the thickness barrier layer. The results show that the average pore-diameter and the thickness of the PAM are 50 nm and 700-800 nm, respectively. And the PAM has an amorphous structure. Comparing with one step anodization, the PAM fabricated using two step andiazation has a higher regulation. The barrier layer can be thinned, and even completely dissolved if the andiazation is continued after Al completely anodized. It is clear that an increase in pore diameter is observed when the immersion time is increased. Contrarily, the interspaces of the PAM are decreased in the 5 wt% H3PO4 solution.Secondly, free-standing nickel (Ni) nanorods were successfully prepared by pulsed electrodeposition on Ti/Si substrate. The length and the morphology of the Ni nanorods can be adjusted by the deposition time. The TEM image reveals that the diameter of the Ni nanorods is about 50 nm and the length is from 500 nm to 800 nm. And the Ni nanorods have a polycrystalline structure. Al was sputtered on the surface of Ni nanorods forming an embedded heterostructure with large contact area. The compositions of the Al/Ni nEM varied with the mass of the Al.Finally, the heart of reaction of the Al/Ni nEM was determined by differential scanning calorimetry (DSC). From three DSC traces with different compositions, there was only one sharp peak in every trace, which is indicative of a quick exothermic reaction. The total heat release of the Al/Ni nEM increased with the rise of Al concentration. During the solid state reaction, not only the AINi phase, but also AlNi3 and Al3Ni2 phases were formed. The 50% firing sensitivity of the Al/Ni nEM was about 36.2 mJ. When it irradiated by single pulse from a laser, it produced sparks which lasted several milliseconds.