An investigation of ceramic coatings for protection of SiC from high-temperature corrosion

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:7257147

Federer, J I

Silicon carbide ceramics are susceptible to corrosion by certain industrial furnace environments. This behavior would limit the use of SiC components in ceramic heat exchangers. Because oxide ceramics corrode substantially less in the same environments, ceramic coatings have been investigated for corrosion protection. Coatings with Al/sub 2/O/sub 3/, SiO/sub 2/, or ZrO/sub 2/ as the main constituent were applied to sintered alpha and recrystallized (CS101) SiC substrates. The coated specimens were thermally cycled between room temperature and 1200/degree/C as a test of adherence. Some coatings adhered better to the inherently rougher CS101 SiC; however, most coatings did not adhere to either substrate. Two Al/sub 2/O/sub 3/-based coatings contained cracks, but remained intact during thermal cycling, and two ZrO/sub 2/-based coatings were subjected to corrosion testing at 1200/degree/C in an oxidizing atmosphere containing Na/sub 2/CO/sub 3/. None of these four coatings exhibited the desired corrosion resistance in this test. Coated samples, however, corroded less than an uncoated sample, indicating that coatings can improve corrosion resistance.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7257147
• Report Number(s): CONF-880724-19; ON: DE88011023
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360205* -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
ADHESION
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBIDES
CARBON COMPOUNDS
CERAMICS
CHALCOGENIDES
COATINGS
CORROSION PROTECTION
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PROTECTIVE COATINGS
SILICA
SILICON CARBIDES
SILICON COMPOUNDS
SILICON OXIDES
THERMAL CYCLING
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES