Preparation And Properties Of Braided Spring/Ceramic Fiber Thermal Barrier Seals

In this paper,based on the requirements for hypersonic vehicles of dynamic flexible thermal barrier seals with elasticity,a novel braided spring/ceramic fiber thermal barrier seals was designed and prepared drawing lessons from the structure of a baseline heatsealing component and the domestic research status of high-temperature ceramic fibers,thermal insulation materials and superalloys.The braided spring/ceramic fiber thermal barrier seals consisted of three parts: superalloy elastic bracket,insulation cotton and braided jacket.The temperature resistance and typical performance of raw materials were firstly discussed and the effect of processing parameters on the elasticity and static insulation properties of thermal barrier seals from room temperature to 900? were also studied.It was finally decided that nickel-based superalloy wires were used for braided elastic bracket,quartz fiber cotton for core and silica fiber yarn for braided jacket,so the temperature resistance of the whole thermal barrier seals could be guaranteedThe results showed that the braided spring/ceramic fiber thermal barrier seals possessed good compression resilience and static heat insulation performance.When prepared with two layers of braided jackets and the density of quartz fiber cotton controlled between 0.05 g/cm3 and 0.2 g/cm3,the spring tube thermal barrier seals reached preferable overall performance.When the compression rate was less than 30%,the seals could be fully rebounded under room temperature and reached a rebound rate more than 85% up till to 900?.The temperature difference between the hot side and the back side of the seals could be over 500?,especially the back side temperature maintained below 200? with the hot side heated to 900? by radiation heating for an hour,which met the needs of certain space thermal sealing technologies.