Molecular dynamic simulations of carbon coated aluminum nanoparticle with core–shell structure for oxidation resistance behaviors and mechanism

Aluminum nanoparticle (ANP) is a promising metal-based additive for solid propellants. However, its high surface activity may cause oxidation and corrosion issues, which could be overcome by coating treatment. In this study, a novel core–shell nano-composite containing carbon coating on ANP surface is modeled and explored by molecular dynamic simulations. Those obtained results show that the coating of carbon on ANP surface could effectively produce the oxidation resistance effect and decline oxidation ratio. The core–shell structure is consisted by Al–C association zone and Al core zone. With enough atomic interactions of the binding effect, inward migration of oxygen is effectively limited. There are two critical factors for the oxidation behavior in this system. One is oxidation temperature, and the other is oxygen pressure. The former one determines the kinetic energy of oxygen and inhibition effect of coating, while the latter one affects the inward migration of oxygen. In addition, this core–shell nano-composite has shown a “self-consuming” effect by eliminating shell atoms even at room temperature oxidation behaviors.