Reliable UHTC Ceramic-Metal Joints for Hypersonic Applications

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.