Diffusion-induced grain-boundary migration in ceria-stabilized tetragonal zirconia polycrystals

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Journal of the American Ceramic Society; (USA)

DOI:https://doi.org/10.1111/j.1151-2916.1991.tb06892.x· OSTI ID:5776744

Schmid, H K ^[1]

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1. Div. of Materials Science and Technology, Council for Scientific and Industrial Research, Pretoria 0001 (ZA)

The microstructure and microchemistry of grain-boundary regions in (CeO{sub 2} + La{sub 2}O{sub 3})-stabilized tetragonal ZrO{sub 2} polycrystals (Ce(La)-TZP) were studied by means of transmission electron microscopy (TEM). Evidence was found for the existence of crystalline and vitreous intergranular phases situated in small pockets at multiple grain junctions and in thin films along grain boundaries. In this ceramic system grain-boundary migration was observed in-situ in the TEM in sample areas subjected to electron irradiation. Interfaces migrated away from their centers of curvature. Evidence was found for Ce de-alloying in the volume swept by the advancing boundaries. It is suggested that the coherency lattice strain brought about by a partial reduction of Ce, resulting in the diffusion of Ce{sup 3 +} along grain boundaries to free surfaces, is the driving force for this phenomenon.

• OSTI ID: 5776744
• Journal Information: Journal of the American Ceramic Society; (USA), Journal Name: Journal of the American Ceramic Society; (USA) Vol. 74:2; ISSN JACTA; ISSN 0002-7820
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALLOYS
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
CHEMISTRY
CRYSTAL LATTICES
CRYSTAL STRUCTURE
GRAIN BOUNDARIES
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MICROSTRUCTURE
MIGRATION
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES