| About this Abstract |
| Meeting |
Materials Science & Technology 2019
|
| Symposium
|
Materials for Nuclear Applications
|
| Presentation Title |
PVD Coating of Surrogate Fuels for Deep Space Nuclear Thermal Propulsion |
| Author(s) |
Maanas Togaru, Thomas Koenig, Gregory B. Thompson |
| On-Site Speaker (Planned) |
Gregory B. Thompson |
| Abstract Scope |
Nuclear thermal propulsion (NTP) is being considered for deep space exploration. However, the use of hydrogen gas as a propellant poses a challenge to the nuclear fuel (used for heating) where upon a deleterious reaction with the fuel can occur. One mitigating strategy to protect the fuel is to provide a conformal coating to serve as a diffusion barrier. Physical vapor deposition (PVD), using magnetron sputtering, has been employed. A rotating drum shifted the ZrO2 powder under a tungsten cathode, with conformal coating thicknesses ranging tens to hundreds of nanometers depending on coating times. As the coating thickened, the film revealed a ‘powdery’ morphology, which is contributed to the impact from powder-on-powder contact during coating. Precession electron diffraction revealed nanocrystalline grains in the coating with no preferred texture. Stoney curvature measurements of W on ZrO2 indicates compressive growth stress states, which will be explained by a kinetic model. |