Thermal insulation and structural reliability of modified epoxy resin‐based ablation thermal protection coatings in aerothermal‐vibration coupling environment

Abstract

AbstractNovel hybrid ablation thermal protection coatings (FHMP‐ATPCs), employing iron trioxide (Fe2O3) powder, hollow glass microspheres, and mica powder as the fillers in hydroxyl‐terminated silicone oligomer‐bridged epoxy resins (PSG) copolymer, is investigated using an aerothermal‐vibration coupling test system. The ablation behavior and structural reliability of FHMP‐ATPCs with varying coating thickness were studied. During the test, the total enthalpy of airflow and dynamic pressures are 23 MJ/kg and 300 Pa, accompanied by the random vibration with a frequency of 20–2000 Hz and a total root‐mean‐square acceleration of 14.9g. The maximum surface and back‐face temperatures of the coating with the thickness of 2 mm reached 836.2°C and 156.4°C, respectively. Results also showed that the reduction of thickness obviously suppressed the surface temperature and increase in back‐face temperature yet maintaining high structural reliability. Compared with DGEBA‐based coatings, the PSG‐based coatings showed excellent structural reliability during the test. The study provides a solution for obtaining high performance ATPCs, which are highly desired for supersonic vehicles.