B2O3-reinforced ablative materials with superior and comprehensive ablation resistance used in aerospace propulsion thermal protection systems

Solid rocket motors (SRMs) have multiple working states, and thermal protection system (TPS) materials used in their combustion chambers must possess high ablation resistance in different ablation environments. However, the currently utilized TPS materials do not fully satisfy this requirement. In this study, the importance of the thermal oxidation protection of a char layer at low temperatures was established for the first time. This was achieved via B2O3 addition, which produced a B2O3 liquid film that considerably improved the char layer performance and ablation resistance of the TPS materials. Typical ablation tests were conducted to demonstrate the superior ablation resistance of B2O3 formulations, and char layer characteristics were analyzed to elucidate the B2O3 reinforcement mechanism. This work opens a new avenue for the design of high-performance TPS materials and presents novel B2O3-reinforced TPS materials with excellent ablation performance, which can help improve the comprehensive performances of TPSs and SRMs.