Ablation‐Immune Thermal Armor Via Microstructural‐Compatibility Design for Extreme Thermal Conditions

To overcome the brittleness and microstructural degradation of ultrahigh temperature ceramics (UHTCs) in hypersonic thermal protection systems, this work develops a C/C‐ZrC‐SiC/ZrC‐SiC composite via a microstructural‐compatibility design that integrates reactive melt infiltration with supersonic atmospheric plasma spraying. Critically, this work strategically incorporated SiC as a dispersed phase in the ZrC coating to actively regulate the deposition thermodynamics and oxidation kinetics, which suppresses the formation of continuous, lamellar ZrO 2 interlayers and mitigates residual stress. Consequently, the designed composite demonstrates exceptional ablation resistance, withstanding oxyacetylene ablation (2200°C) for 3080 s and Ar‐H 2 plasma ablation (2600°C) for 1500 s, while achieving an ultralow linear ablation rate on the order of 10 −5 mm s −1 . This work validates a microstructural‐compatibility‐led design principle, providing a foundational blueprint for developing thermal protection systems.