纳米铝粉氧化机理的反应分子动力学研究进展OA

The combustion mechanism and performance optimization of aluminum nanopowder(ANP)are of great significance to the high-energy propellant industry.In this paper,the microscopic mechanisms and kinetic behaviors of ANP in oxidation,combustion,and coating improvement were systematically reviewed based on the reactive molecular dynamics(RMD)simulation method.The findings reveal that the ReaxFF reactive force field can accurately predict the melting point of ANP(with an error of only 2.9%)and reveal its size dependence and the effect of the oxide layer on the melting process.In the Al-O2 system,the oxidation mechanism of ANP is influenced by the core-to-shell ratio,temperature,oxidant density and flow rate,and ambient pressure.The high core-to-shell ratio,high temperature,high oxygen density,and high flow rate promote the transition from diffusion combustion to microexplosive combustion.In the Al-H2O system,the ANP reactivity is enhanced with decreasing particle size and thinning of the oxide layer,and the introduction of H2O2 can significantly enhance the reaction rate and energy release.Furthermore,the use of capping materials(e.g.,fluoropolymers,carbon nanotubes,ethanol/ether,etc.)has been demonstrated to optimize the storage stability and combustion performance of ANP through mechanisms such as the inhibition of oxidation,the alleviation of sintering,and the promotion of the dissociation of the oxide shell layer.In summary,it is proposed that the transformation of the ANP combustion mechanism under a multi-oxidant coupling environment,composite coating system,and the application of machine learning potential function should be key directions for future research.