Carbon foams for high-temperature thermal protection: oxidation failure and structural modification

Carbon foam is a lightweight porous carbon material with low thermal conductivity and high thermal stability, but its application in thermal protection at high temperatures is restricted by rapid oxidation in oxygen-containing environments. The review summarizes the pore structure, heat transfer behavior, mechanical reliability, and oxidation failure characteristics of carbon foam. The effects of porosity, pore connectivity, ligament thickness, pore wall integrity, and carbon ordering on thermal insulation and oxidation susceptibility were clarified. Second, oxidation protection technologies for carbon foam were classified and discussed in terms of matrix modification and surface coating. Elemental doping, reactive particle incorporation and fiber or whisker reinforcement were reviewed as matrix modification strategies, while glassy, carbide based, boride based, and multicomponent coatings were evaluated as barrier protection approaches. Their protection mechanisms were further distinguished as intrinsic reactivity regulation, oxygen transport control, skeleton stabilization, protective phase formation, and crack healing. Finally, the mechanical properties, thermal insulation retention, density variation, coating integrity, and thermal cycle stability of modified carbon foams were summarized. This review emphasizes the coupled evaluation of oxidation resistance, structural reliability, and insulation performance. Future research should focus on conformal internal pore coatings, standardized coupled testing methods, and scalable integrated matrix and coating designs for long duration service.