降速剂及其作用位点对三组元推进剂燃烧性能的影响规律研究

Two typical burning rate inhibitors (quaternary ammonium salt and adamantane derivative) were selected and the effect of their location on the ignition and combustion performance of propellants was investigated. Using Al@AP and AP@Al composites, different location of inhibitors was designed, which was inside AP particles and on their surface. Scanning electron microscopy (SEM-EDS) and computed tomography (CT) were used to characterize the morphology and structure of prepared composites, and the effects of inhibitors on the heat of explosion, ignition delay time as well as the combustion performance of propellants were studied. The explosion heat of propellants can be decreased by inert inhibitors but this can be partially compensated by the high reactivity of Al@AP composites. Compared with the direct addition of inhibitors in the matrix, the ignition process can be obviously hindered by inhibitors on AP surface. With adamantane derivative on the surface of AP, the ignition delay time of corresponding propellants increased to 420 ms, a 192% extension compared to control group. The burning rates (r) of propellants can be decreased by physically adding inhibitors, but its effect on reducing pressure exponent (n) is limited. A significant reduction of high-pressure r and n value can be obtained by using Al-based composites and inhibitors, for instance, the n value at 1~20 MPa can be reduced from 0.45 (control group) to 0.20 and 0.33 using quaternary ammonium salt and adamantane derivative inside AP, respectively. Accordingly, the n value at 10~20 MPa can be decreased by 48% and 49%, respectively.