Effect of twinning and aging treatment on fatigue process of ZK60 magnesium alloys

Shunsuke Taniguchi, Rumi Kitazawa, Yoshihisa Tanaka, Makoto Yoshida, Susumu Horibe

    Research output: Contribution to journalArticle

    Abstract

    For magnesium alloy ZK60 with different heat treatments, controlled plastic strain amplitude fatigue tests were conducted. Effects of twinning and aging treatments on fatigue process were investigated by analyzing the second derivative of hysteresis half-loop. It is found that during compression the convex peak appears at the strain where twinning begins. It is also found that during tension the convex peak appears at the strain where detwinning begins and the concave peak appears at the strain where slip begins to be predominant. Analyzing the strain at the convex peak in compression at the plastic strain amplitude of 6 × 10-3, for solution treated material and over-aged material twinning hardens with increasing cycle. On the other hand, for T6 material twinning softens from 5 cycle to Nf/5 cycle and then hardens from Nf/5 cycle to Nf/2 cycle. It was suggested that residual twins cause twinning hardening. It was also suggested that cut and dissolution of rod-like precipitates should cause twinning softening. Due to different states of precipitates of materials, the twinning softening appeared for only T6 material at the plastic strain amplitude of 6 × 10 -3. Moreover, the softening were not found for T6 material under the plastic strain amplitude of 4 × 10-3.

    Original languageEnglish
    Pages (from-to)448-454
    Number of pages7
    JournalNippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
    Volume77
    Issue number10
    DOIs
    Publication statusPublished - 2013 Oct

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    Keywords

    • Aging treatment
    • Fatigue test
    • Hysteresis loop
    • Magnesium alloy
    • Twinning

    ASJC Scopus subject areas

    • Mechanics of Materials
    • Materials Chemistry
    • Metals and Alloys
    • Condensed Matter Physics

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