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Evaluation of crack nucleation site and mechanical properties for friction stir welded butt joint in 2024-T3 aluminum alloy

  • Takao OkadaEmail author
  • Masako Suzuki
  • Haruka Miyake
  • Toshiya Nakamura
  • Shigeru Machida
  • Motoo Asakawa
ORIGINAL ARTICLE

Abstract

In this paper, metallographic observations, hardness measurement, and static and fatigue tests were conducted to investigate the discontinuity states which become crack nucleation sites in friction stir welded butt joints in 2-mm-thick 2024-T3 aluminum alloy and static and fatigue properties of the joint. Because different types of surface finish can be used depending on the application of the joint, several types of surface conditions were tested to evaluate their effect on crack nucleation sites and static and fatigue life. Indentation hardness tests revealed that typical hardness reduction is not necessarily observed on the section of the welding line. Based on fatigue test results, it was confirmed that there are several types of crack nucleation sites for friction stir welding (FSW) joints depending on the surface finish, and the features of the fracture surface also differ depending on the site. Furthermore, the type of discontinuity state affects the fatigue life of the FSW joint.

Keywords

Friction stir welding Fatigue strength Aluminum alloy Nucleation site 

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Copyright information

© Springer-Verlag London Limited 2010

Authors and Affiliations

  • Takao Okada
    • 1
    Email author
  • Masako Suzuki
    • 2
  • Haruka Miyake
    • 2
  • Toshiya Nakamura
    • 1
  • Shigeru Machida
    • 1
  • Motoo Asakawa
    • 2
  1. 1.Aviation Program GroupJapan Aerospace Exploration AgencyMitakaJapan
  2. 2.Waseda UniversityShinjukuJapan

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