Fatigue-Life Behavior and Matrix Fatigue Crack Spacing in Unnotched SCS-6/Timetal®21S Metal Matrix Composites

    Volume 17, Issue 3 (July 1995)

    ISSN: 0884-6804

    CODEN: CTROAD

    Page Count: 7


    Hillberry, BM
    Research assistant and professor, Purdue University, School of Mechanical Engineering, West Lafayette, IN

    Herrmann, DJ
    research associate, NASA Langley Research Center, Hampton, VA

    Ward, GT
    Research assistant and professor, Purdue University, School of Mechanical Engineering, West Lafayette, IN

    Abstract

    Fatigue tests of the SCS-6/Timetal®21S composite system were performed to characterize the fatigue behavior for unnotched specimens. The stress-life behavior of the unnotched [0/90]2S laminates was investigated for stress ratios of R = 0.1 and R = 0.3. No difference in fatigue lives was observed when comparing the two stress ratios on a stress-range basis. The unnotched SCS-6/Timetal 21S composites had shorter fatigue lives than those reported in the literature for the SCS-6/Ti-15-3 composites; however, the neat Timetal 21S matrix material had a longer fatigue life than those reported for the neat Ti-15-3. Multiple matrix crack initiation sites were observed throughout the composite, as well as evenly spaced transverse fatigue cracks along the length of the specimens. The spacing between fatigue cracks was investigated, as were the effects of surface cracking on composite stiffness.


    Paper ID: CTR10484J

    DOI: 10.1520/CTR10484J

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    Author
    Title Fatigue-Life Behavior and Matrix Fatigue Crack Spacing in Unnotched SCS-6/Timetal®21S Metal Matrix Composites
    Symposium , 0000-00-00
    Committee D30