Investigation on the Reliability of an Ablation Thermal Protection Coating with Adjustable Thickness under Aerothermal–Vibration Coupling Environment

Abstract

Advanced thermal protection system is the core component of supersonic vehicles. A novel hydroxyl‐terminated silicone oligomer‐bridged epoxy resins (PSG)‐based ablation thermal protection coatings (ATPCs) with different thickness are fabricated. The thermal insulation and structural reliability of the coatings are investigated by an aerothermal–vibration coupling test system. During the test, the heat flux of the surface of ATPCs ranges from 400 to 700 kW m−2. Meanwhile, the vibration load is a random vibration with frequency range of 20–2000 Hz and root mean square of total acceleration (Grms) of 15 g. The maximum surface and back‐face temperatures of the coating with the thickness of 2 mm reach 771.8 and 113.6 °C, respectively. Compared with epoxy resin‐based ATPCs, the PSG‐based ATPCs show excellent structural reliability during the test. Finally, the comprehensive properties of ATPCs with different thickness are also carefully studied. Results show that the reduction of thickness obviously suppresses the surface temperature (≈743.4 °C) and increase in back‐face temperature (≈241.5 °C) yet maintaining much higher structural reliability. This study provides a solution for obtaining excellent thermal insulation performance ATPCs with high structural reliability, which is highly desired in supersonic vehicles.