The Chemical Compatibility Between an Innovative Superhydrophobic and Oleophobic Ultrafine Dry Powder Extinguishing Agent and Representative Aerospace Aluminum Alloy

This study examines the effects of high-temperature oxidation and corrosion on representative aerospace aluminum alloy 2A12, simulating scenarios in aircraft engine compartments. The present research mainly focuses on microsurface morphology, oxidation/corrosion depth, products, kinetics, and reaction mechanisms. Results show that aluminum oxide is the predominant product of both oxidation and corrosion cases. However, the presence of superhydrophobic and oleophobic ultrafine dry powder extinguishing agents accelerates corrosion in the alloy. Surface analysis reveals peak-shaped protrusions and depleted copper regions within the matrix. Interestingly, the maximum corrosion depth surpasses the maximum oxidation depth by 9% after 120 h. Kinetic analysis indicates a power function for the oxidation case and a parabolic function for the corrosion case. The high-temperature oxidation behavior exhibits two stages: nucleation (0-96 h) and rapid oxidation (96-120 h). Similarly, the thermal corrosion progresses through an initial slow incubation stage (0-48 h) followed by an accelerated corrosion stage (48-120 h). Detailed chemical reaction mechanisms are provided to elucidate the observed phenomena. These findings enhance our understanding of high-temperature oxidation and corrosion in aerospace aluminum alloys, offering valuable insights for design and protection strategies in aircraft engine compartments.