Fabrication and creep properties of eutectic-composition Al2O3/YAG/YSZ sintered composites

Three-phase alumina/YAG/yttria-stabilized cubic zirconia (YSZ) composites were fabricated by a solid-state reaction route starting from commercial powders of Al2O3, Y2O3 and monoclinic ZrO2. The final phases Al2O3, YAG and YSZ were obtained after calcination of the powder mixtures at 1400 °C. Dense...

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Detalles Bibliográficos
Autores: Huamán-Mamani, F. A., Jiménez Holgado, C., Jiménez Melendo, Manuel
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2021
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/153265
Acceso en línea:https://hdl.handle.net/11441/153265
https://doi.org/10.1016/j.jeurceramsoc.2021.07.055
Access Level:acceso abierto
Palabra clave:Alumina
Composite material
Creep
Grain boundary sliding
Microstructure
Descripción
Sumario:Three-phase alumina/YAG/yttria-stabilized cubic zirconia (YSZ) composites were fabricated by a solid-state reaction route starting from commercial powders of Al2O3, Y2O3 and monoclinic ZrO2. The final phases Al2O3, YAG and YSZ were obtained after calcination of the powder mixtures at 1400 °C. Dense bulk composites were obtained after sintering, with a homogeneous microstructure of fine and equiaxed grains with sizes of 1 μm. Compressive mechanical tests were performed at 1300–1450 °C in air at constant load and at constant initial strain rate. A brittle-to-ductile transition was found with increasing temperature. Grain boundary sliding is the main deformation mechanism in the ductile regime, characterized by a stress exponent of 2 and by the absence of dislocation activity and changes in grain morphology. Alumina seems to be the rate-controlling phase owing to the improvement in creep resistance by the presence of yttrium and zirconium of the other two phases.