Abstract A newly parameterized reactive force field with low gradient correction (ReaxFF-lg) is used to simulate the thermal decomposition of RDX systems. Pure Al, surface nitrided Al (AlN) and surface oxidized Al (AlO) particles are constructed to mix with RDX. The simulation results indicate that the decomposition mechanism of pure RDX is the elimination of HONO in the initial stage and the elimination of -NO2 in the later stage. The mechanism is further testified by the density functional calculation. RDX molecule adsorbs on the surface of Al particles to form N Al and O Al bonds. N O bond ruptures is the main decomposition ways of aluminiferous RDX in the initial stage. The decompositions of RDX and RDX/AlO need to overcome 2.00 kJ/g and 0.31 kJ/g energy barrier, respectively. However, there are no energy barriers in RDX/Al and RDX/AlN decomposition processes. Aluminiferous RDX decomposition depends on the strong attraction of Al to N and O. Alumina layer blocks the attraction of Al to O and N in RDX, causing the reactivity of AlO declines significantly. However, the Al-nitride layer hardly has such blocking effect, resulting AlN maintains the reactivity of Al.

中文翻译：

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含铝RDX复合材料热分解的分子反应动力学模拟

摘要 一个新参数化的低梯度修正反作用力场 (ReaxFF-lg) 用于模拟 RDX 系统的热分解。纯铝、表面氮化铝 (AlN) 和表面氧化铝 (Al2O) 颗粒用于与 RDX 混合。模拟结果表明，纯RDX的分解机理是初期去除HONO，后期去除-NO2。密度泛函计算进一步证明了该机制。RDX分子吸附在Al颗粒表面，形成N Al和O Al键。NO键断裂是含铝RDX初期分解的主要方式。RDX 和 RDX/Al2O 的分解需要分别克服 2.00 kJ/g 和 0.31 kJ/g 能垒。然而，RDX/Al 和 RDX/AlN 分解过程中没有能垒。含铝RDX的分解依赖于Al对N和O的强烈吸引力。氧化铝层阻止了RDX中Al对O和N的吸引力，导致Al2O的反应性显着下降。然而，Al-氮化物层几乎没有这种阻挡作用，所产生的AlN保持了Al的反应性。