Nucleation in stress-induced tetragonal-monoclinic transformation of constrained zirconia

Conference · Sat Aug 01 00:00:00 EDT 1992

OSTI ID:7253527

Chan, S K

A theory for stress-induced tetragonal{yields}monoclinic transformation of constrained zirconia is presented based on the assumption that when forcibly strained to a regime of absolute instability where the free energy density of the tetragonal phase has a negative curvature, the constrained tetragonal zirconia becomes unstable with respect to the development of a modulated strain pattern that will evolve into a band of twin monoclinic domains. The temperature range for such an instability, the critical size of the inclusion, the corresponding critical strain, and the periodicity of the modulation are derived in terms of parameters that can be related to the elastic stiffness coefficients of various orders of the inclusion and the shear modulus of the host matrix. An entirely different mechanism is suggested for the reverse monoclinic{yields}tetragonal transformation because the monoclinic phase is metastable when the extrinsic stress is removed. Estimates for the parameters are inferred from a variety of experimental data for pure zirconia and the numerical values for the predicted physical quantities are obtained.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 7253527
• Report Number(s): ANL/CP-75749; CONF-9208144--2; ON: DE92040720
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CHALCOGENIDES
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
INCLUSIONS
INSTABILITY
MONOCLINIC LATTICES
NUCLEATION
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
STRESSES
TETRAGONAL LATTICES
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES