SODIUM-GRAPHITE INTERACTION AND GRAPHITE PROTECTIVE COATINGS
Molten sodium attacks artificial graphites, causing dilation and, under some conditions, decrepitation. Because of the anisotropy of extruded grsphite, dilation perpendicular to the extrusion axis is slightly greater than parallel to the extension axis. At 600 to 1OOO deg F, sodium is initially nonwetting to graphite, but becomes wetting in a matter of minutes. The liqiud soaks into the pores of the graphite through chemisorption and intergranular penetration; in- terlamellar compounds or complexes may also be formed. Coatings and coating techniques were investigated for the protection of graphite from attack by molten sodium. The coatings examined included chromium, nickel, zirconium, zirconium carbide, tungsten carbide, silicon carbide, silicon nitride, and molybdenum disilicide. None of the coatings, tested by soaking in static sodium at 1OOO deg F, gave satisfactory protection. Failure in all cases resulted from continuous porosity or cracks in the coating material. (auth)
- Research Organization:
- Atomics International. Div. of North American Aviation, Inc., Canoga Park, Calif.
- DOE Contract Number:
- AT-11-1-GEN-8
- NSA Number:
- NSA-15-019737
- OSTI ID:
- 4069496
- Report Number(s):
- NAA-SR-6094
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-61
- Country of Publication:
- United States
- Language:
- English
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