| Abstract: | Studying the combustion characteristics and properties of the condensed phase products of aluminum particles is significant for the application of aluminum‐based propellants. The microstructure, particle size distribution, specific surface area and metallic Al contents of three different samples were analyzed by scanning electron microscopy, laser particle size analyzer, nitrogen adsorption and inductively coupled plasma atomic emission spectroscopy. The thermal oxidation characteristics of the samples were also studied by a thermal analyzer. A dynamic combustion test system was used to study the combustion process in motion and the properties of the products. The results show that as the activation energy of the sample decreases, the initial reaction temperature decreases during the thermal analysis. Moreover, the thermal oxidation degree increases with the decrease in particle size. In the dynamic combustion process, the combustion efficiency of the sample was calculated by using the temperature distribution in the combustion process, and the calculated results were in good agreement with the results of ICP measurements. With the increase in the particle size of the samples, the heat release was reduced, and the agglomerationand oxidation degree of the condensed phase products were also decreased. By increasing the feeding amount, the combustion temperature and the combustion efficiency would increase. The reaction mechanism in the dynamic furnace involves not only the diffusion reaction, but also the melt‐dispersion reaction. The initial reaction temperature of sample A was between 500∼600 °C, the combustion temperature was between 900∼1000 °C, the ignition delay time was around 270 ms, and the reaction time was about 0.6s. |
