Oxidation and Ablation Resistance, Ablation Mechanism of Novel Ti ₃ AlC ₂ Modified Al‐Coated Carbon Fiber/Boron Phenolic Resin Ceramizable Composites

ABSTRACT Carbon fiber/phenolic resin composites (CF/Ph) have attracted great attention as large‐area thermal protection materials for hypersonic vehicles, due to their high specific strength and ease of manufacture. However, carbon fibers are prone to oxidation failure above 400°C, severely limiting their application. Herein, Ti ₃ AlC ₂ modified Al‐coated carbon fiber/boron phenolic resin ceramizable composites (ACF/BPRC) were fabricated via a facile prepreg compression molding technique. The effects of Ti ₃ AlC ₂ and Al coating on thermal degradation behavior, long‐term oxidative corrosion resistance, and ablation resistance were investigated. The ceramizable composites demonstrated excellent thermal stability, with a residue yield of 82.3% at 1500°C and a linear ablation rate (LAR) as low as 0.00573 mm/s under 4.3 MW/m ² . The ablation mechanism was revealed through microstructure evolution, phase evolution, and thermodynamic calculations. Through high‐temperature in situ ceramization reactions, a Ti–Al–O–C multiphase ceramic thermal protection barrier was formed, endowing the ceramizable composites with exceptional ablation resistance.