Chemical compatibility of some ceramic matrix composite structures with fusion reactor helium coolant at high temperatures
- Univ. of California, Los Angeles, CA (United States)
The thermodynamic stability of SiC/SiC composite structures proposed for fusion applications is presented in this paper. Minimization of the free energy for reacting species in the temperature range 773-1273 K is achieved by utilizing the NASA-Lewis Chemical Equilibrium Thermodynamics Code (CET). The chemical stability of the matrix (SiC), as well as several potential fiber coatings are studied. Helium coolant is assumed to contain O{sub 2} and water moisture impurities in the range 100-1000 ppm. The work is applied to recent Magnetic and Inertial Confinement Conceptual designs. The present study indicated that the upper useful temperature limit for SiC/SiC composites, from the standpoint of high-temperature corrosion, will be in the neighborhood of 1273 K. Up to this temperature, corrosion of SiC is shown to be negligible. The main mechanism of weight loss will be by evaporation to the plasma side. The presence of a protective SiO{sub 2} condensed phase is discussed, and is shown to result in further reduction of high-temperature corrosion. The thermodynamic stability of C and BN is shown to be very poor under typical fusion reactor conditions. Further development of chemically stable interface materials is required.
- OSTI ID:
- 197014
- Report Number(s):
- CONF-940664-; TRN: 95:005767-0188
- Resource Relation:
- Conference: ISFNT-3: international symposium on fusion nuclear technology, Los Angeles, CA (United States), 27 Jun - 1 Jul 1994; Other Information: PBD: 1994; Related Information: Is Part Of Third international symposium on fusion nuclear technology; PB: 362 p.
- Country of Publication:
- United States
- Language:
- English
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