High-temperature precipitation hardening of Y/sub 2/O/sub 3/ partially-stabilized ZrO/sub 2/ (Y-PSZ) single crystals

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Acta Metallurgica; (USA)

OSTI ID:5575344

Heuer, A H ^[1]; Lanteri, V ^[2]; Dominguez-Rodriguez, ^[3]

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1. Case Western Reserve Univ., Cleveland, OH (USA)
2. Institut de Recherches de la Siderurgie Francaise (IRSID), 78 - Saint-Germain-en-Laye (France)
3. Departamento de Fisica Materia Condensada Facultad Fisica, Apartado 1065, 41080 Sevilla (ES)

Precipitation hardening in two-phase 4.5 m/o Y/sub 2/O/sub 3/ partially-stabilized ZrO/sub 2/ (Y-PSZ) single crystals has been studied at 1400{sup 0}C, using crystals at 1600{sup 0}C for various times up to 150 h. The aging allowed the formation and growth of low-solute tetragonal (t)-ZrO/sub 2/ precipitates in a high-solute cubic (c)-ZrO/sub 2/ solid solution matrix. These colony precipitates are internally twinned on {110}, and form fiber-like morphologies (fiber axis along <001>) at the longest annealing times; the lamellar spacing within the colonies coarsens via conventional Ostwald ripening. Surprisingly, even large precipitates (> 1{mu}m long) are coherent. All crystals deformed by nucleation and propagation of Luders bands, leading to serrated flow. The yield stress increases linearly with lamellar spacing and reaches the very high value of 550 MPa (at 1400{sup 0}C) for the 150 h sample. The particular dislocation-precipitate interactions leading this exceptionally potent precipitation hardening are discussed.

• OSTI ID: 5575344
• Journal Information: Acta Metallurgica; (USA), Journal Name: Acta Metallurgica; (USA) Vol. 37:2; ISSN 0001-6160; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
&amp; Refractories-- Structure &amp; Phase Studies
360204 -- Ceramics
Cermets
&amp; Refractories-- Physical Properties
AGE HARDENING
ANNEALING
CHALCOGENIDES
CRYSTALS
DISLOCATION PINNING
DISPERSIONS
HARDENING
HEAT TREATMENTS
HIGH TEMPERATURE
MIXTURES
MONOCRYSTALS
MORPHOLOGY
NUCLEATION
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
SOLID SOLUTIONS
SOLUTIONS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES