Effect of high-temperature hydrogen exposure on sintered. alpha. -SiC

Journal Article · Tue Mar 01 04:00:00 EST 1988 · Advanced Ceramic Materials; (USA)

DOI:https://doi.org/10.1111/j.1551-2916.1988.tb00194.x· OSTI ID:6070901

Hallum, G W; Herbell, T P ^[1]

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1. NASA - Lewis Research Center, Cleveland, OH (USA)

Sintered {alpha}-SiC was exposed to hydrogen containing 25 ppm H{sub 2}O at high temperatures for up to 500 h. Weight loss and corrosion were seen after 50 h at temperatures as low as 1,000{degree}C. Corrosion of SiC produced grain-boundary deterioration at 1,100{degree}C and a mixture of grain and grain-boundary deterioration at 1,300{degree}C. Statistically significant strength reductions were seen in samples exposed to hydrogen for times >50 h and temperatures above 1,100{degree}C. Fracture origins, identified by fractography, were associated with areas of general grain-boundary corrosion at 1,100{degree}C transitioning to corrosion pits at 1,300{degree}C. A maximum strength decrease of {approx} 33% was seen at 1,100{degree} and 1,300{degree}C after 500 h exposure to hydrogen. A computer-assisted thermodynamic program was used to predict possible reaction products of SiC, hydrogen, and H{sub 2}O.

• OSTI ID: 6070901
• Journal Information: Advanced Ceramic Materials; (USA), Journal Name: Advanced Ceramic Materials; (USA) Vol. 3:2; ISSN 0883-5551; ISSN ACEME
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330201 -- External Combustion Engines-- Stirling Cycle
36 MATERIALS SCIENCE
360205* -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
CARBIDES
CARBON COMPOUNDS
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPUTER CODES
CORROSION
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
EXPERIMENTAL DATA
FRACTOGRAPHY
GRAIN BOUNDARIES
HYDROGEN
INFORMATION
MEASURING METHODS
MICROSCOPY
MICROSTRUCTURE
NONMETALS
NUMERICAL DATA
SCANNING ELECTRON MICROSCOPY
SCATTERING
SILICON CARBIDES
SILICON COMPOUNDS
VERY HIGH TEMPERATURE
X-RAY DIFFRACTION