Vitreous joining of SiC fiber reinforced SiC composites

Technical Report · Fri Dec 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/6973365· OSTI ID:6973365

Coon, D N ^[1]

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1. Wyoming Univ., Laramie, WY (USA). Dept. of Mechanical Engineering

Glass in the MgO--Li{sub 2}O--Al{sub 2}O{sub 3}--SiO{sub 2} system were developed to as brazing materials to join SiC fiber reinforced SiC composites. These glass materials will melt and flow at temperatures ranging from 1000{degree}C to 1200{degree}C, and are chemically compatible with SiC. The glass transition temperature and melting temperature can be altered by adjusting the MgO:Li{sub 2}O ratio. The glasses exhibited viscous deformation at their glass transition temperatures, 490{degree}C to 725{degree}C. The glasses were devitrified to develop crystalline phases based on {beta}{prime}-spodumene, {beta}{prime}-eucryptite, or a {beta}{prime}-spodumene-{beta}{prime}-eucryptite solid solution. Glass-ceramics, prepared by thermal treatment, exhibited no viscous deformation to temperature as high as 785{degree}C, and exhibited improved strength as the test temperature was increased. Joints were prepared by painting the composite surface with a slurry of the glass powder suspended in water. Joining temperature, joining time, glass composition, amount of joining glass, and post-joining heat treatments were the variables examined. Larger quantities of joining glass and shorter joining times were observed to improve joint strength. The addition of niobium oxide to the glass also improved joint strength. The niobium oxide also stabilizes the glass/composite interface at temperatures less than 1200{degree}C.

• Research Organization: EG and G Idaho, Inc., Idaho Falls, ID (USA)
• Sponsoring Organization: DOE/NE
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 6973365
• Report Number(s): EGG-MS-8933; ON: DE90012951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360602 -- Other Materials-- Structure & Phase Studies
360603 -- Materials-- Properties
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BRAZING
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
FABRICATION
FIBERS
FLEXURAL STRENGTH
FRACTURE PROPERTIES
GLASS
JOINING
LITHIUM COMPOUNDS
LITHIUM OXIDES
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MATERIALS
MECHANICAL PROPERTIES
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
REINFORCED MATERIALS
SILICON CARBIDES
SILICON COMPOUNDS
SILICON OXIDES
TRANSITION ELEMENT COMPOUNDS
WELDING