树脂基防隔热一体化热防护复合材料高温性能演变分析OACHSSCDCSTPCD

The resin-based integrated thermal protection composite(PF/CF-HT01)was prepared using sol-gel atmospheric drying method,with heat-resistant phenolic resin(PF)as the matrix and carbon fiber braid(CF)as the composite material.The thermal stability and high-temperature mechanical properties of the material were studied using thermogravimetric analysis(TG)and an electronic universal testing machine.Ablation resistance of the material was evaluated using an oxyacetylene device,while the microstructure evolution of the material was examined through scanning electron microscopy(SEM)and X-ray diffraction(XRD).The results showed that the initial decomposition temperature of the resin matrix was 387.3 ℃,with a maximum decomposition temperature of 644.7 ℃.The residual carbon rate was 13.8％at 800 ℃.For the composite material,the initial decomposition temperature was 405.3 ℃,and the residual carbon rate reached 42.8％at 800 ℃.The compressive strength of the composite material was 542.6 MPa at room temperature.After in-situ heat treatment at 1 000 ℃ for 30 s and 60 s,the maximum compressive strengths were 166.2 MPa and 149.9 MPa,respectively.The composite material exhibited excellent thermal insulation integration performance,with a line ablation rate of 0.039 mm/s.After a single thermal shock assessment,the back temperature remained below 100 ℃,and even after continued thermal conduction,the maximum back temperature did not exceed 200 ℃.The rapid carbonization of the material under high-temperature conditions,leading to the formation of dense SiO2 and BN porcelain layer,conferred outstanding ablation resistance and scouring resistance.Meanwhile,the underlying layer retained its porous structure,maintaining good thermal insulation properties.