Molecular dynamics investigation of thermite reaction behavior of nanostructured Al/SiO2 system
JP Zhang and YY Zhang and H Li and JX Gao and XL Cheng, ACTA PHYSICA SINICA, 63, 086401 (2014).
In this study we have investigated the thermite reaction of Al/SiO2 layered structure by classical molecular dynamics simulation in combination with the reactive force field function. Under the adiabatic conditions, we simulate the structural changes and energetic properties of the system at six different initial temperatures (600, 700, 800, 900, 1000 and 1100 K). These results show that the thermite reaction of Al/SiO2 is the self-heating reduction-oxidation (redox) reaction. When the initial temperatures are 900 and 1000 K, the Al layers change into liquid-like structure under melting points. The thermite reaction happens with a much faster rate. At other initial temperatures such as 600, 700, 800 and 1100 K, the thin Al-O layer at the interface is quite weak for the higher initial temperature. The adiabatic reaction temperature increases and the effective reaction time decreases with the increasing of the initial temperature. the reaction self-heating rates are 3.4, 3.5, 4.7 and 5.4 K/ps for the initial temperatures of 600, 700, 800 and 1100 K, respectively. The results reveal that the thermite reaction self-heating rates depend on the thickness of interfacial diffusion barrier in the nanoparticle. In addition, the thermite reaction of the Al/SiO2 system leaves the Si, which accord well with the experimental result.
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