Research on the ablation damage evolution of Al2O3/PF composite coatings deposited by supersonic plasma spraying on resin matrix surfaces

As a key component in modern defense weapon systems, resin-based insulating supports are indispensable in electromagnetic rail launchers. Although they exhibit excellent mechanical properties and electrical insulation, their poor ablation and erosion resistance limits their application in harsh service environments. In this study, Al₂O₃/PF composite coatings were successfully fabricated by alternately spraying Al₂O₃ and Al₂O₃/PF powders onto glass fiber-reinforced epoxy resin substrates using a supersonic plasma spraying system. Ablation behavior and degradation were investigated under varying ablation distances and ablation times. Response surface models were established to correlate ablation distance and cycle number with coating performance, including elastic modulus, hardness, and surface morphology, and to explore the spatiotemporal evolution and underlying mechanisms of coating degradation during ablation. The results indicate that coatings ablated at a distance of 110 mm exhibited superior performance compared to those at 90 mm and 100 mm. At distances of 90 mm and 100 mm, complete surface carbonization occurred after 100 and 150 ablation times. In contrast, at 110 mm, the degree of carbonization gradually increased with the number of ablation times. The constructed response surfaces revealed the spatiotemporal characteristics of the ablation-induced damage. These findings provide important theoretical insights into the damage evolution mechanisms of composite coatings and offer a basis for evaluating the performance and failure behavior of resin-based insulating supports in extreme environments.