Abstract: In response to the application requirements of thermal protection materials for hypersonic aircraft engines, this paper investigates the performance of three-dimensional reinforced quartz fiber/phenolic resin gradient thermal insulation materials. The preform is prepared using a 2.5D weaving/needle combined process, and the molding is carried out using a resin vacuum infusion process. Various tests and analyses were conducted on the mechanical properties, thermophysical properties, and ablation performance of the material. The results showed that when the total thickness was constant, the intermittent distribution of the weaving layer and the web layer along the thickness direction had a significant impact on the overall performance of the material. When the number of layers was small, its ablation performance was better, and when the number of layers was large, its thermophysical properties were better. The tensile and compressive mechanical properties were mainly affected by the distribution of the web layer and its interface with the weaving layer. The gradient thermal insulation material proposed in this article has the advantages of light weight, good anti-ablation performance, strong mechanical properties, and excellent resistance to airflow erosion, providing more material references for aerospace thermal protection engineering.

Key words: thermal protection, three-dimensional reinforce, thermal insulation, gradient material, composites