Investigation of common aircraft alloy corrosion behavior and mechanism by the potential halon replacement fire suppressant C ₂ F ₅ I

This study investigated the kinetics and mechanisms of high-temperature corrosion of common aerospace alloys, such as those used in aircraft engines and fuselage skins, when locally exposed to the fire extinguishing agent C 2 F 5 I.The aim is to elucidate the material degradation process and to assess the efficacy of C 2 F 5 I as a halon replacement in aerospace applications. The results of the study showed that at 200 °C, C 2 F 5 I was compatible with all metals tested with no significant corrosion. However, at temperatures above 300 °C, the thermal decomposition of C 2 F 5 I produced C1–C4 fluorinated hydrocarbon products that resulted in significant corrosion of the alloys. Among these alloys, 2024 exhibits the best corrosion resistance, which shows that the performance of Al-based alloys is better than that of Fe-based alloys and Cu-based alloys. Based on these findings, the most heavily corroded alloy, H62, was selected for further analysis of corrosion products and gas by-products. The mechanism of Cu alloy corrosion by C 2 F 5 I at elevated temperatures was elucidated. The results provide valuable insights for performance evaluation and selection of halon alternatives.