Advanced Ceramic Matrix Composite Leading Edge Materials and Processing for Hypersonic Vehicles

ABSTRACT: In previous work for MDA and the Army, Navy, and Air Force, Ultramet demonstrated the fabrication of carbon fiber-reinforced refractory carbide matrix composites for missile and railgun projectile nosetip and aeroshell applications using a rapid, low-cost melt infiltration process. The composite materials have undergone extensive high temperature testing under laser and arcjet heating conditions and have exhibited low or no erosion when tested to nearly 2900°C. The composites have also exhibited extremely high toughness and thermal shock resistance and have good potential for operation in adverse weather. Stability in rain, snow, and hail is a critical issue for hypersonic vehicles, and Ultramet composite materials have performed very well in hydrometeor and nylon bead impact tests conducted by NASA MSFC. Coatings and conventional ceramic matrix composites (CMC) are much more prone to impact damage, whereas Ultramet CMCs have established resistance to oxidation, weather erosion, and thermal shock. In this project, Ultramet will team with aerospace systems developer and manufacturer Raytheon (component selection, requirements definition) and with Materials Research and Design (component design and analysis) to establish the feasibility of utilizing well-established melt infiltration processing of ultrahigh temperature CMC materials that offer reduced weight and increased performance as well as improved manufacturability over silicon- or boron-containing CMCs for hypersonic vehicle leading edges. Initial CMC designs will be established for the selected component(s) and a prototype will be fabricated and subjected to high temperature oxidation testing at the Air Force LHMEL facility. BENEFIT: The proposed use of rapidly manufactured high temperature ceramic matrix composite leading edge components can play a key role in achieving hypersonic vehicle manufacturability and cost goals as well as weight and performance objectives. Readily available materials that require little development time are critical. In addition to monolithic CMC structures such as nosetips and fins, the potential exists to combine the CMC with Ultramet"s structural foam insulation to produce integrated airframe/thermal protection system aeroshell structures. Ultramet CMCs, produced by a rapid, low-cost melt infiltration process, have demonstrated outstanding performance in multiple test series, including those performed under the Composites and Advanced Materials (CAM) and Hypersonic Flight Demonstration (HyFly) programs among others. Other potential aerospace applications include launch vehicle propulsion systems and aerobraking structures for planetary exploration. Potential commercial applications include high temperature, low-mass insulating structures for heat cycle and gas turbine engines, scramjet and ramjet engine components, and furnace heat recovery units (recuperators).