Volume 5, Issue 8 (September 2008)

    Effect of Prestrain on Fatigue Crack Growth of Age-Hardened Al 6061-T6

    (Received 11 November 2007; accepted 8 July 2008)

    Published Online: 2008

    CODEN: JAIOAD

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    Abstract

    The effect of prestrain on fatigue crack growth characteristic (FCGC) of age-hardened Al 6061-T6 was investigated. Al 6061-T6 specimens were subjected to tension to produce plastic strain. Extruded bars were prepared to investigate FCGC. Specimens with an artificial hole from the bar were used to observe Mode I fatigue crack. On the other hand, coarse-grained plain specimens were used and observed for Mode II fatigue crack. Fatigue tests were performed under a rotating bending load (R=−1). The experimental results showed the Mode I fatigue crack growth rates decelerated a little due to prestrain. However, in the case of Mode II, fatigue crack growth rates of prestrain specimens accelerated about ten times due to prestrain. The Mode II fatigue crack easily propagates on the slip bands, because precipitation particles on the slip bands are sheared by prestrain. The result means the influence of prestrain on Mode II fatigue should be taken into account for damage-tolerant design.


    Author Information:

    Ikematsu, Koji
    Department of Mechanical Engineering Science, Kyushu University, Nishi-ku, Fukuoka

    Mishima, Takuhiro
    Department of Mechanical Engineering Science, Kyushu University, Nishi-ku, Fukuoka

    Kang, Minwoo
    Department of Mechanical Engineering Science, Kyushu University, Nishi-ku, Fukuoka

    Aono, Yuuta
    Department of Mechanical Engineering Science, Kyushu University, Nishi-ku, Fukuoka

    Noguchi, Hiroshi
    Department of Mechanical Engineering Science, Kyushu University, Nishi-ku, Fukuoka


    Stock #: JAI101549

    ISSN: 1546-962X

    DOI: 10.1520/JAI101549

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    Author
    Title Effect of Prestrain on Fatigue Crack Growth of Age-Hardened Al 6061-T6
    Symposium Seventh International ASTM/ESIS Symposium on Fatigue and Fracture Mechanics (36th ASTM National Symposium on Fatigue and Fracture Mechanics), 2007-11-16
    Committee E08