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Aluminum (Al) is widely used to improve the combustion performance of energetic material formulations. However, only a limited part of the energy released by the oxidation of aluminum works because of ignition delay and incomplete combustion. In order to overcome this defect, a mechanical activation-sintering method is developed to prepare Al/PTFE composites for enhancing the combustion performance of Al powders. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) are used to analyze the morphology and structures of the samples. An orthogonal experiment is employed to filter the best preparation parameters by evaluating the combustion pressure in a closed vessel. With the conditions of 65 : 35 (g/g, mass ratio of Al and PTFE), 12 : 1 (g/g, ball-to-powder weight ratio, BPR), 250 rpm (rotation speed of ball milling container) and 45 min (milling duration), the Al powders are coated uniformly by PTFE and the composites exhibit excellent dispersity. By optimizing the preparation conditions, the maximum pressure, pressurization rate as well as the flame propagation are highly improved, compared to that of a simple mixture of Al powders and PTFE. This work provides a feasible and universal method to prepare aluminum-containing composites. [ABSTRACT FROM AUTHOR]

To improve the ignition and combustion properties of n‐Al powders, n‐Al/Ni composite particles were prepared by replacement reaction under alkaline environment. In the anhydrous ethanol system, the effect of solution parameters on sample preparation was studied, and the preparation technology of n‐Al/Ni was accordingly optimized. The chemical constituents, phase, morphology and combustion performances of n‐Al/Ni were characterized by chemical titration, XRD, SEM, EDS and combustion duration test, respectively. The results showed that the optimized replacement reaction method can modify the n‐Al powders by nickel well, and it was appropriate to use OH−1 corresponding to consume 60 % alumina in the n‐Al powders and Ni2+ equal to 12.35 % mass fraction of n‐Al powders. It can be seen from the SEM images that the samples have a dispersive spherical morphology with a uniform distribution of nickel overall the samples. And the XRD results confirmed that nickel exists in the samples as a metallic substance. The results of chemical titration indicated that the content of active aluminum in the optimal sample was slightly higher than that of raw n‐Al, but considering Ni, the content of reactive substance in the sample was greatly increased. The combustion duration test also proved that the combustion performance of n‐Al/Ni was significantly improved. In conclusion, the improved properties promise a further enhanced prospect of n‐Al in energetic materials. [ABSTRACT FROM AUTHOR]