Enhanced oxidation and combustion of aluminum powder enabled by the stress-chemical synergy of thickness-controllable F2314 coatings

To overcome the oxidation limitation and incomplete combustion of micron-sized aluminum caused by its native oxide shell, an F2314 nanocoating was constructed on 1 μm spherical Al particles by electrostatic spray granulation. Molecular dynamics simulation and experimental characterization showed that F2314 possessed the highest interfacial binding energy with Al among the F23-series fluoropolymers and formed a continuous, uniform, and thickness-controllable coating. Compared with bare Al, Al@F2314 exhibited earlier oxidation, enhanced deep oxidation, and faster energy release. The 1.0 wt% sample showed the best performance, with mass gains of 7.4% and 72.5% in the initial and deep oxidation stages, while the apparent activation energies decreased from 194.7 and 304.3 kJ·mol−1 to 154.8 and 203.9 kJ·mol−1, respectively. Its maximum pressure and pressurization rate increased by 23.65% and 69.34%, the ignition delay shortened to 2.00 ms, the burning rate reached 2.46 cm·s−1, and the energy-release efficiency rose to 96.91%. The enhancement originates from thermo-mechanical pre-weakening of the oxide shell, fluorination-induced destabilization during decomposition, and facilitated outflow and deep oxidation of molten Al at high temperature.