Dual-matrix fiber-reinforced lightweight ablative thermal protection composites with outstanding micron-scale ablative recession

Abstract

Abstract Developing lightweight thermal protection materials that can efficiently resist ablation and provide heat insulation in extreme aerodynamic heating environments remains a significant challenge for ensuring aerospace safety. Fiber-reinforced polymer composites (FRPs) are a crucial choice for thermal protection materials due to their lightweight nature and excellent thermal insulation properties. However, the application is limited by ablative recession despite their unique sacrificial thermal protection mechanism. This study introduces an innovative fiber-reinforced composite with distinct matrices for the upper and lower regions. The upper matrix consists of a silicone-based ceramicizable resin mixed with high-temperature-resistant fillers, while the lower matrix incorporates a porous phenolic aerogel with a high residual carbon rate. In comparison to conventional ablative thermal protection materials, the linear ablation setback can be significantly reduced, reaching levels as low as 0.11 µm/s and 6 µm/s for ablations at 1.5 MW and 3.6 MW, respectively. Furthermore, these materials exhibit exceptional dynamic ablation thermal insulation and repeatability over a certain number of cycles. This approach offers a fresh perspective on the design and preparation of lightweight ablative thermal protection materials, breaking through the limitations of ablation setback and expanding the application scope of such materials in aerospace vehicles.