(国防科技大学 航天与材料工程学院,
国防科技重点实验室, 长沙 410073)
摘 要: 针对固体火箭发动机喉衬的使用工况, 提出并采用先驱体转化法制备了一种新型的复合材料, 2D Cf/SiC-Cu材料(其中Cu作为发汗剂),对其力学性能和烧蚀性能进行了考察。 结果表明: 采用先驱体转化法可以制备出力学性能较好的2D Cf/SiC-Cu材料,弯曲强度、 剪切强度和断裂韧性分别达到263 MPa, 27.7 MPa和15.7 MPa·m1/2。 材料密度为2.24 g/cm3, 在氧乙炔焰中烧蚀60 s后, 材料结构保持完整,力学性能仍能满足喉衬材料的使用要求, 质量损失为0.124 g。 因此, 2D Cf/SiC-Cu材料具有较低的密度、良好的力学性能和较好的抗烧蚀性能, 是一种有希望的固体火箭发动机喉衬备选材料。
关键字: 2D Cf/SiC-Cu材料; 先驱体转化; 烧蚀性能; 力学性能
( Key Laboratory of Advanced Ceramic Fibers and Composites,
College of Aerospace and Materials Engineering,
National University of Defense Technology, Changsha 410073, China)
Abstract: Based on the working environments of the solid rocket nozzle throat, a proposal to improve anti-ablative property of 2D Cf/SiC composites by introduction of Cu into C/SiC composites and decreasement of surface temperature through Cu transpiration was presented. 2D Cf/SiC-Cu composites were prepared by precursor infiltration and pyrolysis. The mechanical properties and ablative properties were investigated. The flexural strength, shear strength and fracture toughness of the 2D Cf/SiC-Cu composites reach 263 MPa, 27.7 MPa and 15.7 MPa·m1/2, respectively. The desity of the samples is 2.24 g/cm3, and the samples mass loss is 0.124 g when exposed for 60 s in a flowing oxyacetylene torch environment. The mechanical properties of 2D Cf/SiC-Cu composites could still satisfy the requirements of the solid rocket nozzle throat. Compared to other throat materials, 2D Cf/SiC-Cu composites has lower density and better ablative properties.
Key words: 2D Cf/SiC-Cu composites; preceramic polymer pyrolysis; ablative properties; mechanical properties