Ablation Behavior and Numerical Simulation of Multiphase Synergistic Ceramization‐Enhanced Silicone Rubber Composites

High‐speed vehicles encountered severe aerodynamic heating during flight, posing significant challenges to material performance. Flexible TPM maintained structural integrity under severe thermal strain, but their ablation resistance still required improvement. Therefore, this work employed a multiphase synergistic ceramization enhancement strategy through the PDC approach by incorporating a synthesized CP into silicone rubber‐based composites to achieve in situ ceramization during ablation. By introducing Hf and Si at the molecular level, the effects of CP content on the thermal decomposition behavior, structural evolution, and ablation performance were systematically investigated. The results indicated that a moderate amount of CP increased the initial thermal decomposition temperature and promoted the formation of multiphase ceramic structures within the char layer. These in situ formed ceramic phases enhanced the density and structural stability of the char layer, thereby improving ablation performance. At a CP content of 1 phr, the MAR and LAR decreased by 9.5% and 53%, respectively. To further reveal the thermochemical evolution mechanism under extreme thermal environments, a thermal‐fluid‐ablation coupled multiphysics model was developed. The simulated surface and backside temperature profiles showed good agreement with the experimental results, and the deviations in MAR and LAR were within 10%, confirming the accuracy and reliability of the model.