先驱体转化法制备2D C_f/SiC-Cu复合材料及其性能

Preparation and properties of 2D C_f/SiC-Cu composites produced by precursor infiltration and pyrolysis

针对固体火箭发动机喉衬的使用工况,提出在Cf/S iC体系中引入Cu,通过Cu发汗降低材料表面温度以提高材料的抗烧蚀性能。采用先驱体转化法制备了铜体积分数分别为2.18%、4.86%和6.53%的新型复合材料,同时考察了其力学性能和烧蚀性能。结果表明,随着铜含量的增加复合材料试样的弯曲强度逐渐下降,分别为261.07M Pa、203.61M Pa、164.91M Pa;试样的断裂韧性也逐渐下降,分别为13.4M Pa.m1/2、12.5M Pa.m1/2、11.8M Pa.m1/2。三种复合材料试样在氧乙炔焰烧蚀30s后,试样结构均保持完整,弯曲强度分别下降到121.16M Pa、140.23M Pa、122.87M Pa,质量烧蚀率分别为0.036g/s、0.050g/s、0.064g/s。与其他喉衬材料相比,2D Cf/S iC-Cu材料密度低、力学性能和抗烧蚀性能好,具有良好的应用前景。

In order to meet the working requirements of a solid rocket nozzle throat, the anti-ablative properties of 2D Cf/SiC composites have been improved by decreasing surface temperature by Cu boil-off in ablative conditions. 2D Cf/SiC-Cu composites with different Cu contents （2.18 vol%, 4.86 vol%, 6.53 vol % ） were prepared via precursor infiltration and pyrolysis, and their mechanical and ablative properties were investigated. Results indicated that with increasing Cu content, the flexural strength decreased from 261. 07 MPa to 203.61 MPa to 164.91MPa, and the fracture toughness also decreased from 13.4MPa·m^1/2 to 12.5 MPa·m^1/2 to 11.8 MPa ·m^1/2. The composites all retained structural integrity after 30 seconds ablation in an oxyacetylene torch, but flexural strength decreased to 121.16MPa to 140.23 MPa to 122.87 MPa, and the corresponding mass ablations were 0.036 g/s, 0. 050 g/s and 0.064 g/s. The 2D Cf/SiC-Cu composites have low density, high strength and low ablative loss compared with other throat materials.