Plastic deformation and self diffusion in Y-CSZ single crystal

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6072994

Cheong, Deock-Soo

Plastic deformation of Y{sub 2}O{sub 3}-stabilized cubic ZrO{sub 2} (Y-CSZ) single crystals was studied using the load-interruption technique during compression tests at 1400{degree}C. The crystals were oriented to activate the single slip system, (001)<110>. Slip trace analysis, dislocation etch pits and dislocation structure analysis gave the complete explanation of plastic behavior of this crystal. The very high work-hardening in the microplasticity region resulted from formation of sessile dipoles and loops. The yield drop in this crystal occurred by dislocation multiplication via the activation of secondary dislocation rather than by conventional dislocation multiplication. The plastic deformation continued by activating additional slip systems without appreciable work hardening at 1400{degree}C. Finally in the zero work hardening region, the dislocation nucleation rate was competitive with the annihilation rate keeping the constant dislocation density. The effect of temperature on the plastic deformation of this crystal was studied by compression tests between 1200 and 1500{degree}C. The results were in agreements with that of 1400{degree}C in that similar dislocation structures formed. However, the lower temperatures induced higher dislocation densities due to lower dislocation annihilation. The single crystals were also deformed using the different orientations to activate other slip systems. The effect of strain rate on the plastic deformation was studied at two different strain rates. Plastic deformation of Y-CSZ single crystals is strongly dependent on temperature, strain-rate, and orientation.

• Research Organization: Case Western Reserve Univ., Cleveland, OH (USA)
• OSTI ID: 6072994
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
&amp; Refractories-- Mechanical Properties
ANNEALING
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DEFORMATION
DIFFUSION
DISLOCATIONS
HEAT TREATMENTS
LINE DEFECTS
MECHANICAL PROPERTIES
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PLASTICITY
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES