Metallic Joining to Advanced Ceramic Composites

Currently, advanced ceramic composites are state-of-the-art for hypersonic airbreathing and space propulsion applications. The Launch Abort System (LAS) of the Orion Multi-Crew Exploration Vehicle (MCEV) will provide a safe escape for the crew in the event of an emergency during launch. A key component of the LAS is its Attitude Control Motor (ACM) containing numerous advanced ceramic composite subcomponents. To fully utilize the high specific strengths and temperature capabilities of these composites, reliable high-temperature joining techniques are needed for attachment to metallic structures. Typical joining technologies such as epoxy, brazing and soldering are not useful in high-temperature applications. Currently, pintles and hot structures are mechanically fastened through highly stressed joints to metallic rods and actuators. Mechanical fastening is not an ideal solution since it causes stress concentrations and destruction of continuous fibers by through holes and threads reducing the mechanical properties of the composite structure. A solution that will resolve joining of numerous composites to metallic components is being pursued. During Phase I, techniques to join metallic structures to advanced ceramic composites will be investigated resulting in structural qualification testing for the ACM pintle assembly. During Phase II, ACM hot gas components will be fabricated and hot fire tested.