Novel Rapid Prototyping Technique for the Fabrication of Structural Components

Advanced ceramics research (ACR), has developed a simple, highly promising thruster fabrication method utilizing novel gel casting and injection molding techniques. These methods will be used for the creation of low-cost thrusters and nozzles. Thefollowing proposal details a synergistic combination of the two technologies to create a thermal protection system concept that is low-cost and innovative. In order to create the initial mold, an ACR patented method called Wax Dip Molding (WDM) involvingCNC-machining a model of the desired component from a block of special water soluble polymer blend material developed at ACR followed by casting/solidifying molten wax around the machined model. This mold will be filled with ACR's patented fibrous monolith(FM) Zirconium diboride-BN) fibers embedded in a gel-casting slurry of Zirconium Carbide with the water-soluble mandrel material. Subsequently, Zirconium Carbide with water soluble binder will be injection molded around the Fibrous Monolith-gelcastingcomponent. During binder burnout, the water-soluble binder foams, creating a closed cell porosity foam structure thus creating an in-situ thermal protection system that is well-bonded to the underlying ceramic composite liner. The water-soluble mandrelmaterial will be completely burnt out also, thus providing a simple method to make a high-temperature ceramic thruster with foam skin.The anticipated markets for complex-shaped high temperatures ceramic/ceramic foam components with the highest growthpotential are: aerospace, defense propulsion technologies, and electrical insulation applications. For the US government, the potential applications are in (a) thruster housings with foam skins for thermal protection, (b) combustors, (c) hot gas ducts, (d)exhaust flaps, (e) rocket nozzle throats, (f) radiant burners, and (g) solar thermal propulsion engines. ACR has already established close supplier and development relationships with a number of relevant manufactures that include Aerojet, Thiokol, AlliantTech, and Raytheon.During the Phase I program ACR will work closely with these companies for evaluating the performance vs cost requirements to turn this process into a commercial success. The fabrication of components using this material system for other non-thrustercomponents including turbine engine nozzle parts, and aircraft structures exposed to turbine engine reversing thrusters is a possibility. This method of producing thermal protection systems for thruster technology is totally innovative and will advance thetechnology tremendously.