Dopant effect on high-temperature plastic flow behavior and grain boundary chemistry in oxide ceramics

Hidehiro Yoshida, Yuichi Ikuhara, Taketo Sakuma

    Research output: Contribution to journalArticlepeer-review

    Abstract

    The grain boundaries in high-purity oxide ceramics, such as Al 2O3 and TZP, are often free from glass phase, and the high-temperature plastic flow or grain boundary failure is sensitive to small levels of doping by various cations. For example, the high-temperature creep strain rate in fine-grained, polycrystalline Al2O3 is highly retarded by 0.1 mol% Lu3+ or Zr4+-doping. The elongation to failure in superplastic TZP is improved by 0.2-3 mol% Ge 4+-doping. Such a dopant effect is attributed to changes of the grain boundary diffusion due to the segregation of dopant cation along the grain boundaries. Quantitative analysis on the atomic structure and chemical bonding state along the grain boundaries by high-resolution electron microscopy, energy-dispersive X-ray spectroscopy, electron energy-loss spectroscopy and molecular orbital calculations will provide theoretical guiding principles to design high-performance oxide ceramics in the near future.

    Original languageEnglish
    Pages (from-to)108-116
    Number of pages9
    JournalZeitschrift fuer Metallkunde/Materials Research and Advanced Techniques
    Volume96
    Issue number2
    DOIs
    Publication statusPublished - 2005 Feb

    Keywords

    • Alumina
    • Creep
    • Grain boundary
    • Superplasticity
    • TZP

    ASJC Scopus subject areas

    • Condensed Matter Physics
    • Physical and Theoretical Chemistry
    • Metals and Alloys
    • Materials Chemistry

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