Investigation of fatigue crack initiation in Ti-6Al-4V during tensile-tensile fatigue

  • Svetlana G. Ivanova
  • Ronald R. Biederman
  • Richard D. SissonJr.
Article

Abstract

Fatigue crack initiation in Ti-6Al-4V has been investigated in high cycle fatigue (HCF) and low cycle fatigue (LCF) regimes at stress ratio R=0.1 using the replication technique. In all four tested α/β microstructures, the crack was initiated by fracture of equiaxed alpha grain. Fractured alpha grains are seen on the fracture surface as flat facets with features characteristics of cleavage fracture. In the regime of low stress amplitudes and in the absence of reverse loading, cleavage fracture contributes to crack initiation and early stages of crack growth in Ti-6Al-4V. This mechanism is discussed in relation to the anomalous mean stress fatigue behavior exhibited by this alloy.

Keywords

fatigue crack initiation fatigue of Ti-6Al-4V mean stress effects microstructure 

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Copyright information

© ASM International 2002

Authors and Affiliations

  • Svetlana G. Ivanova
    • 1
  • Ronald R. Biederman
    • 1
  • Richard D. SissonJr.
    • 1
  1. 1.Materials Science and Engineering Program, Mechanical Engineering DepartmentWorcester Polytechnic InstituteWorcesterU.S.A.

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