Comparative study of the estimation of creep crack growth behaviour of TiAl by using a precrack and a notch CT specimens

A. Toshimitsu Yokobori, Masayuki Shibata, Masaaki Tabuchi, Akio Fuji

    Research output: Contribution to journalArticlepeer-review

    7 Citations (Scopus)

    Abstract

    The fatigue crack growth behaviour of Ti-48.2%Al intermetallics (full lamellar structure) strongly depends on the microstructure, that is lamellar alignment, and it grows along the lamellar direction. Therefore, it is difficult to introduce a straight fatigue precrack in a CT specimen to provide a standardized specimen for the estimation of the crack growth rate. Concerning high temperature creep brittle materials, since notch opening displacement at the time of creep crack initiation is small, a sharp notched specimen can keep similar stress singularity as a fatigue precracked specimen. In this paper, comparative research on the characteristics of creep deformation and crack extension was performed by using a fatigue precracked and a sharp notched CT specimens. Based on this result, a mechanical model was constructed and finite element stress analyses on the creep deformation for both specimens were performed. By these analytical results, the different behaviour of the characteristics of creep deformation and crack extension between a precrack and a sharp notch specimens were verified mechanically. Furthermore, the validity of using a sharped notched CT specimen to estimate creep crack growth rate was assured for creep brittle materials.

    Original languageEnglish
    Pages (from-to)57-62
    Number of pages6
    JournalMaterials at High Temperatures
    Volume15
    Issue number2
    DOIs
    Publication statusPublished - 1998 Jan 1

    Keywords

    • Precracked and notched CT specimens

    ASJC Scopus subject areas

    • Ceramics and Composites
    • Condensed Matter Physics
    • Mechanics of Materials
    • Mechanical Engineering
    • Metals and Alloys
    • Materials Chemistry

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