ABSTRACT To address the issues of aluminum (Al) powder agglomeration during combustion and low oxidizer decomposition efficiency in composite solid propellants, this study utilized in situ self‐assembly technology to prepare cobalt‐based hybrid‐coated modified Al powder (Al@CZ). It systematically investigated its regulatory mechanism on the combustion performance of ammonium perchlorate (AP) and ammonium dinitramide (ADN)‐based propellants. Characterization results indicate that Co 2+ and 2‐methylimidazole form an amorphous coating layer at the dopamine polymerization interface, with variable thickness accompanied by a gradient of Co 2+ loading. Thermal analysis shows that the modified Al may trigger a thermite reaction at the interface in air, reducing the high‐temperature oxidation peak. The modified Al exhibits significant catalytic efficiency for the high‐temperature decomposition of AP, with the activation energy reduced by up to 34.7% and the peak temperature advanced by 78°C. However, its catalytic effect on ADN is relatively weak. In the propellant system, Al@CZ reduces the width of the exothermic peak of AP‐based propellants, increases the burning rate by 10.4%, and decreases the median particle size of the condensed‐phase products by 92.1%; for ADN‐based propellants, it significantly improves combustion stability, with the maximum pressure increasing by 1.1 times and the pressure rise rate improving by 6.4 times. Combustion mechanism analysis confirms that the coating accelerates Al core oxidation and reduces combustion surface residence time through the synergistic effect of catalytic decomposition of oxidants and interfacial thermite reactions, effectively suppressing molten agglomeration. This study provides a new strategy for controllable combustion regulation in high‐energy solid propellants.
Chen et al. (Wed,) studied this question.