Boehmite and yttrium oxide coatings on silicon nitride from aqueous sols

Conference · Fri Aug 01 04:00:00 EDT 1997

OSTI ID:501007

Buchta, M; Shih, W H ^[1]

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1. Drexel Univ., Philadelphia, PA (United States). Dept. of Materials Engineering

To improve the processing of silicon nitride, boehmite and yttrium oxide were coated on silicon nitride particles by an aqueous sol-gel method. It is shown that boehmite and Y{sub 2}O{sub 3} can be coated on Si{sub 3}N{sub 4} particles from aqueous solutions. However, the Y{sub 2}O{sub 3} coating is not as complete as boehmite coating. The coating of a yttria coating followed by a boehmite coating was attempted and the TEM showed a coating twice as thick as the Y{sub 2}O{sub 3} or AlOOH coating. Hydrothermal treatment of yttrium nitrate hydrous hydroxide results in the formation and growth of Y(OH){sub 3} fibers which can be calcined and transformed into Y{sub 2}O{sub 3} fibers at 500 C.

• OSTI ID: 501007
• Report Number(s): CONF-960401--; ISBN 1-55899-335-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM HYDROXIDES
ALUMINIUM OXIDES
CERAMICS
FABRICATION
FIBERS
MATERIALS HANDLING
PROTECTIVE COATINGS
SILICON NITRIDES
SOL-GEL PROCESS
YTTRIUM OXIDES