Journal of Power System Engineering (동력기계공학회지)

The Korean Society for Power System Engineering (한국동력기계공학회)
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Marco and Microscopic Observations of Fatigue Crack Growth in Friction Stir Welded 7075-T651 Aluminum Alloy Plates

마찰교반용접된 7075-T651 알루미늄 판재의 피로균열전파의 거시적 및 미시적 관찰

  • Kong, Yu-Sik (A+ LINC, Pukyong National University) ;
  • Kim, Seon-Jin (Department of Mechanical & Automotive Engineering, Pukyong National University)
  • 공유식 (부경대학교 A+ LINC 사업단) ;
  • 김선진 (부경대학교 기계자동차공학과)
  • Received : 2014.01.02
  • Accepted : 2014.03.25
  • Published : 2014.04.30
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Abstract

In this paper, in order to investigate the effects of marco and microscopic observations of fatigue crack growth in friction stir welded (FSWed) 7075-T651 aluminum alloy plates, fatigue crack growth tests were performed under constant amplitude loading condition at room temperature with three different pre-cack locations, namely base metal (BM-CL) and two kinds of pre-crack locations in welded joints, weld metal (WM-CL) and heat affected zone (HAZ-CL) specimens. The fatigue crack growth behavior of FSWed 7075-T651 aluminum alloy plates were discussed based on the marco and microscopic fractographic observations. The marcoscopic aspects of surface crack growth path for BM-CL and HAZ-CL specimens indicate relatively straight lines, however, the crack growth paths of WM-CL specimens grow first straight and by followed toward the TMAZ and HAZ. The microscopic aspects of fatigue fracture for BM-CL and HAZ-CL specimens indicate typical fatigue striation, but WM-CL showed intergranular fracture pattern by micro structural changes of FSW process.

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References

  1. W. M. Thomas, E. D. Nicholas, J. C, Needham, M. G. Church, P. Templesmith, and C. J. Dawes, "Friction Stir Butt Welding", International Patent Appl. No. PCT/GB92/02203 and GB Patent Appl. No. 9125978.8; December 1991. US Patent No. 5,460,317; October 1995.
  2. R. S. Mishra and Z. Y. Ma, 2005, "Friction Stir Welding and Processing", Materials Science and Engineering, R50, pp. 1-78.
  3. Friction Welding Working Group, 2006, "Friction Welding Technology", Ilgan-gongup-shinmun-sa, pp. 176-264.
  4. C. O. Kim and S. J. Kim, 2011, "Effects of Welding Condition on Tensile Properties of Friction Stir Welded Joints of Al-7075-T651 Plate", Journal of The Korean Society for Power System Engineering, Vol. 15, No. 2, pp. 61-68.
  5. C. O. Kim, H. J. Sohn and S. J. Kim, 2011, "Effects of Welding Condition on Hardness and Microstructure of Friction Stir Welded Joints of Al-7075-T651 Plate", Journal of The Korean Society for Power System Engineering, Vol. 15, No. 3, pp. 58-64. https://doi.org/10.9726/kspse.2011.15.3.058
  6. Y. H. Jeong and S. J. Kim, 2013, "Spatial Randomness of Fatigue Crack Growth Rate in Friction Stir Welded 7075-T651 Aluminum Alloy Welded Joints", Transaction of Korean Society for Mechanical Engineers, Vol. 37, No. 9, pp. 1109-1116. https://doi.org/10.3795/KSME-A.2013.37.9.1109
  7. S. H. Ahn and S. J. Kim, 2013, "Statistical Distribution of Fatigue Crack Growth Rate for Friction Stir Welded Joints of Al7075-T651", Journal of The Korean Society for Power System Engineering, Vol. 17, No. 4, pp. 86-93.
  8. H. J. K. Lemmem, R. C. Alderliesten and R. Benedictus, 2011, "Marco and Microscopic Observations of Fatigue Crack Growth in Friction Stir Welded Aluminum Joints", Engineering Fracture Mechanics, Vol. 78, pp. 930-943. https://doi.org/10.1016/j.engfracmech.2011.01.018
  9. ASTM E647-05, 2005, "Standard Test Method for Measurement of Fatigue Crack Growth Rates", Annual Book of ASTM Standards, Vol. 3.01, ASTM International.
  10. S. S. Kim, C. G. Lee and S. J. Kim, 2008, "Fatigue Crack Propagation Behavior of Friction Stir Welded 7083-H31 and 6061-T651 Aluminum Alloys", Materials Science and Engineering A478, pp. 56-64.
  11. P. C. Paris and F. Erdogan, 1963, "A Critical Analysis of Fatigue Crack Growth Propagation", Transaction of ASME, Journal of Basic Engineering, Vol. 85, pp. 528-536. https://doi.org/10.1115/1.3656900

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