Martensitic transformation in zirconia

Subbarao, E. C.; Maiti, Himadri Sekhar; Srivastava, Krishna

doi:10.1002/pssa.2210210102

Cited by 259 publications

(90 citation statements)

References 72 publications

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“…This mechanism was adopted by [BT93,ST96], who constructed the corresponding energy function and investigated the distortion of the p-T phase diagram under the influence of non-hydrostatic stresses. In spite of the internal consistency of the corresponding model, the t-o orientation relationships reported experimentally for zirconia by [SMS74,BFV91] indicate that the 44 Crelated mechanism may not be the one at work in ZrO 2 . What is perhaps more important, this mechanism does not allow for the presence of orthorhombic zirconia, and, ultimately, of the t-o-m triple point, in the phase diagram of the crystal.…”

Section: Introductionmentioning

confidence: 89%

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Elastic crystals with a triple point

Truskinovsky¹,

Zanzotto²

2002

Journal of the Mechanics and Physics of Solids

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The peculiar behavior of active crystals is due to the presence of evolving phase mixtures the variety of which depends on the number of coexisting phases and the multiplicity of symmetryrelated variants. According to Gibbs' phase rule, the number of phases in a single-component crystal is maximal at a triple point in the p-T phase diagram. In the vicinity of this special point the number of metastable twinned microstructures will also be the highest -a desired effect for improving performance of smart materials. To illustrate the complexity of the energy landscape in the neighborhood of a triple point, and to produce a workable example for numerical simulations, in this paper we construct a generic Landau strain-energy function for a crystal with the coexisting tetragonal (t), orthorhombic (o), and monoclinic (m) phases. As a guideline, we utilize the experimental observations and crystallographic data on the t-o-m transformations of zirconia (ZrO 2 ), a major toughening agent for ceramics. After studying the kinematics of the t-o-m phase transformations, we re-evaluate the available experimental data on zirconia polymorphs, and propose a new mechanism for the technologically important t-m transition. In particular, our proposal entails the softening of a different tetragonal modulus from the one previously considered in the literature. We derive the simplest expression for the energy function for a t-o-m crystal with a triple point as the lowest-order polynomial in the relevant strain components, exhibiting the complete set of wells associated with the t-o-m phases and their symmetry-related variants. By adding the potential of a hydrostatic loading, we study the p-T phase diagram and the energy landscape of our crystal in the vicinity of the t-o-m triple point. We show that the simplest assumptions concerning the order-parameter coupling and the temperature dependence of the Landau coefficients produce a phase diagram that is in good qualitative agreement with the experimental diagram of ZrO 2 .

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Section: Introductionmentioning

confidence: 89%

“…(A) The best-established t-m orientation relationship for ZrO 2 indicates that the fourfold axis of the tetragonal phase is parallel to the two-fold axis of the monoclinic phase (see [SMS74,BFV91]). This means that monoclinic ZrO 2 comes from a variant structure with point group M 3 .…”

Section: An Example: Zirconiamentioning

confidence: 99%

Elastic crystals with a triple point

Truskinovsky¹,

Zanzotto²

2002

Journal of the Mechanics and Physics of Solids

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“…It must be noted, however, that mechanical properties (fundamental in diverse applications) of pure bulk zirconia at high temperatures are poor due to the martensitic phase change from the monoclinic to the tetragonal form [25]. Nevertheless, the introduction of different divalent or trivalent cations ('stabilizers') in place of zirconium stabilizes the tetragonal and the cubic forms versus the monoclinic one [26].…”

Section: Introductionmentioning

confidence: 99%

Large scale synthesis of nanostructured zirconia-based compounds from freeze-dried precursors

Gómez¹,

Villanueva²,

Vie³

et al. 2013

Journal of Solid State Chemistry

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a b s t r a c tNanocrystalline zirconia powders have been obtained at the multigram scale by thermal decomposition of precursors resulting from the freeze-drying of aqueous acetic solutions. This technique has equally made possible to synthesize a variety of nanostructured yttria or scandia doped zirconia compositions. SEM images, as well as the analysis of the XRD patterns, show the nanoparticulated character of those solids obtained at low temperature, with typical particle size in the 10-15 nm range when prepared at 673 K. The presence of the monoclinic, the tetragonal or both phases depends on the temperature of the thermal treatment, the doping concentration and the nature of the dopant. In addition, Rietveld refinement of the XRD profiles of selected samples allows detecting the coexistence of the tetragonal and the cubic phases for high doping concentration and high thermal treatment temperatures. Raman experiments suggest the presence of both phases also at relatively low treatment temperatures.

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“…[1][2][3] The cubic phase of ZrO 2 with the fluorite structure (c-ZrO 2 ) is stable at high temperature from 1430 to 2650 K, and further addition of metal oxides such as Y 2 O 3 , CaO and MgO can stabilize the cubic phase at lower temperatures. [4][5][6][7][8][9][10] The doping of such di-or trivalent cations gives rise to formation of oxygen vacancies due to chargeneutrality requirement of the whole systems, 11) and the oxygen vacancies are able to diffuse easily through the lattice.…”

Section: Introductionmentioning

confidence: 99%

Effects of Dislocations on the Oxygen Ionic Conduction in Yttria Stabilized Zirconia

et al. 2004

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Ionic conductivities of yttria-stabilized zirconia (YSZ) single crystals deformed at high-temperature were measured by the AC impedance method. A correlation between ionic conductivity and dislocation structures of deformed YSZ single crystals were investigated. Electrical conductivity measurements of the deformed YSZ crystals were performed for two different current directions of [1 1 10] and [ 1 1 1 11]. The [1 1 10] direction is parallel to edge dislocations introduced by the primary slip system, while the [ 1 1 1 11] direction is normal to the edge dislocation lines. Transmission electron microscopy observations showed that the dislocations due to the primary slip system of (001) [110] were mainly generated at the strain of around 1% strain, while the secondary slip systems, such as (1 1 1 1 1)[101] and (1 1 11)[011], were also activated at about 10% strain. It was found that the deformed samples with larger strains exhibited higher electrical conductivities irrespective of the measured current directions. However, the electrical conductivity along [ 1 1 1 11] was higher than that along [1 1 10], suggesting that mobility of oxygen ion is sensitive to the dislocation structures. From the activation energy for oxygen diffusion in the deformed samples, it was found that the oxygen migration enthalpy for deformed samples became smaller than that for undeformed samples, whereas the association enthalpy for the deformed samples became larger. The increase in the association enthalpy might be due to interaction between oxygen vacancies and dislocations. It is thus considered that oxygen vacancies concentrate around dislocations, and are able to move very quickly along the dislocation lines.

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Martensitic transformation in zirconia

Cited by 259 publications

References 72 publications

Elastic crystals with a triple point

Elastic crystals with a triple point

Large scale synthesis of nanostructured zirconia-based compounds from freeze-dried precursors

Effects of Dislocations on the Oxygen Ionic Conduction in Yttria Stabilized Zirconia

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