Performance of CVD and CVR coated carbon-carbon in high temperature hydrogen

Technical Report · Fri Dec 31 00:00:00 EST 1993

DOI:https://doi.org/10.2172/10116346· OSTI ID:10116346

Adams, J. W.; Barletta, R. E.; Svandrlik, J.; Vanier, P. E.

As a part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings which will be time and temperature stable at extremely high temperatures in flowing hydrogen. These coatings must protect the underlying carbon structure from attack by the hydrogen coolant. Degradation which causes small changes in the reactor component, e.g. hole diameter in the hot frit, can have a profound effect on operation. The ability of a component to withstand repeated temperature cycles is also a coating development issue. Coatings which crack or spall under these conditions would be unacceptable. While refractory carbides appear to be the coating material of choice for carbon substrates being used in PBR components, the method of applying these coatings can have a large effect on their performance. Two deposition processes for these refractory carbides, chemical vapor deposition (CVD) and chemical vapor reaction (CVR) have been evaluated. Screening tests for these coatings consisted of testing of coated 2-D and 3-D weave carbon-carbon in flowing hot hydrogen at one atmosphere. Carbon loss from these samples was measured as a function of time. Exposure temperatures up to 3,000 K were used and samples were exposed in a cyclical fashion, cooling to room temperature between exposures. The results of these measurements are presented along with an evaluation of the relative merits of CVR and CVD coatings for this application.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: Department of Defense, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 10116346
• Report Number(s): BNL-49299; ON: DE94005451; TRN: AHC29403%%7
• Resource Relation: Other Information: PBD: [1993]
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
FUEL DISPERSION REACTORS
COATED FUEL PARTICLES
ZIRCONIUM CARBIDES
CHEMICAL VAPOR DEPOSITION
HYDRIDATION
NIOBIUM CARBIDES
TANTALUM CARBIDES
SPACE POWER REACTORS
SPACE PROPULSION REACTORS
CORROSION RESISTANCE
THERMAL CYCLING
EXPERIMENTAL DATA
210600
360201
360205
POWER REACTORS, MOBILE, PROPULSION, PACKAGE, AND TRANSPORTABLE
PREPARATION AND FABRICATION
CORROSION AND EROSION