High Temperature Fracture Characterization for Sensors Operating in Extreme Environments (043542)

This project is focused on quantifying high temperature fracture and cyclic fatigue of ceramic and metallo-ceramic materials for developing pressure sensors that can operate at temperatures in excess of 1000◦C. This information will be used to transition an optical pressure sensor design from basic science research to a fully functional sensor for use in high temperature wind tunnel testing and future commercialization. A significant amount of the sensor development (e.g., design, fabrication, calibration, and testing) has been done by a collaborator, Prof. Mark Sheplak, at the University of Florida. The proposed research builds upon this prior research collaboration from a Department of Energy Manufacturing Program and an FAA Center of Excellence on Commercial Space Transport. The key piece missing that will move this technology from the laboratory to sensor implementation is to understand high temperature fracture and fatigue mechanics experienced during aerodynamic loading in extreme environments (i.e., hypersonic flight). This is due to a weak spot in the design which has experienced delamination between a sapphire diaphragm and the platinum interface that serves as glue to the sensor body. The platinum adheres the sapphire using spark plasma sintering which has not been optimized. We expect the new knowledge of high temperature fracture toughness will provide sensor designers with important information that guides sensor design geometry and enhances the manufacturing processes and thus minimize the risks of fracture and fatigue over a broad temperature and pressure range.