Ultra-high-temperature ceramic (UHTC) composites hold great potential for use as leading edges and nose tips in hypersonic and atmospheric re-entry vehicles. UHTC composites must be joined to themselves and to aerospace alloys to integrate the leading edges and nose tips into the airframe. The objective of this project is to develop a reliable bonding process to join UHTC composites to Ti-based metallic components that can withstand aerothermal heating during the flight of hypersonic vehicles, which presents an extreme environment due to aerodynamic heating and shock wave interactions. In Phase I we will formulate a family of braze alloys and form UHTC composite/Ti-alloy joints. The microstructures of the joints will be examined by X ray diffraction, electron microscopy and electron spectroscopy. Microhardness measurements across the joint region will be performed. Room and high temperature mechanical properties of the joints will be measured, and a potential joint design will be presented.
Benefit: The proposed joining technology has the potential to produce more reliable joints under extreme working conditions, such as corrosive and high temperature conditions. The new bonding technology for UHTC composites to Ti-alloys will not only be useful for DoD applications but also other harsh environment and high temperature industrial applications. These applications include nuclear reactors, ceramic heat exchangers and process equipment in chemical industries, heating elements, engine and gas turbine components, and chemical propulsion components for space applications. Perhaps a more widespread application would be UHTC composite/metal components for corrosive applications in metal and chemical processing industries. Such components would include high efficiency heat exchanger tubes, chemical and slurry pumps, and seals.
Keywords: Ceramic-Metal joint, Ceramic-Metal joint, Extreme environment, Missile, hypersonic, UHTC composite, Leading Edge
