Fatigue Crack Propagation Behavior of Fine Grained Al-5083 Alloy Produced by Severe Plastic Deformation

강소성법을 이용한 미세립 Al-5083 합금의 피로균열전파 거동

  • Published : 2007.04.30


Fine grained Al-5083 alloy produced by equal channel angular pressing (ECAP) at $120^{\circ}C$ was tested for investigating mechanical properties and crack growth propagation behavior. Also, FEM stress and strain analysis for the samples during ECAP were investigated, using a plastic deformation analysis software DEFORM 2-D. Coarse grained as-received samples exhibited UTS of 255.6MPa with a elongation to failure of 34.4%. By contrast, the ECAPed fine grained samples exhibited UTS of 362.0MPa with a elongation to failure of 12.9%. Fatigue crack growth resistance and threshold of fine grained samples were lower than that of as-received coarse grained samples. The higher fatigue crack growth rate in the fine grained ECAPed samples may partially arise from small roughness closure effect due to smoother fracture surfaces.


5083-Al alloy;fine-grained microstructure;FEM simulation;fatigue crack growth rate


  1. S.L. Semiatin, D.P. DeLo, 'Equal channel angular extrusion of difficult-to-work alloys' Mater. & Designs, Vol. 21, pp. 311-322, 2000 https://doi.org/10.1016/S0261-3069(99)00085-0
  2. M.K. Rabinovich, M.V. Markushev, 'Influence of fine grained structure and superplastic deformation on the strength of aluminum alloys', J. Mater. Sci. Vol. 30, pp. 4692-4702, 1995 https://doi.org/10.1007/BF01153080
  3. Y. Iwahashi, M. Furukawa, Z. Horita, M. Nemoto, T.G. Langdon, 'Microstructural characteristics of ultrafine-grained aluminum produced using equalchannel angular pressing' Met. & Mater. Trans. A, Vol. 29A, pp. 2245-2252, 1998
  4. ASTM E647-93: Standard test method for measurement of fatigue crack growth rates
  5. V. Patlan, A. Vinogradov, K. Higashi, K. Kitagawa, 'Overview of fatigue properties of fine grain 5056 Al-Mg alloy processed by equal-channel angular pressing' Mater. Sci. Eng. A Vol. 300, pp. 171- 182, 2001 https://doi.org/10.1016/S0921-5093(00)01682-8
  6. DEFORM2D, Scientific Forming Technologies Corporation
  7. M. Furukawa, Z. Horita, M. Nemoto, R.Z. Valiev, T.G. Langdon, 'Microhardness measurements and the Hall-Petch relationship in an Al-Mg alloy with submicrometer grain size' Acta Metall. et Mater., Vol. 44, pp. 4619-4629, 1996 https://doi.org/10.1016/1359-6454(96)00105-X
  8. A. Vinogradov, S. Nagasaki, V. Patlan, K. Kitagawa, M. Kawazoe, 'Fatigue properties of 5056 Al-Mg alloy produced by equal-channel angular pressing', Nano Struct. Mater. Vol. 11 No. 7, pp. 925-934, 1999 https://doi.org/10.1016/S0965-9773(99)00392-X
  9. V.M.. Segal, 'Materials processing by simple shear', Mater. Sci. Eng. A, Vol. 197, pp. 157-164, 1995 https://doi.org/10.1016/0921-5093(95)09705-8
  10. S.R. Agnew, J.R. Weertman, 'Cyclic softening of ultrafine grain copper' Mater. Sci. Eng. A, Vol. 244, pp. 145-153, 1998 https://doi.org/10.1016/S0921-5093(97)00689-8
  11. D.H. Shin, K.H. Oh, W.J. Kim, S.W. Lee, W.Y. Choo, 'ECAP강가공에 의한 0.15%C강의 결정립 미세화', 대한금속학회지, Vol. 37, pp. 1048- 1054, 1999
  12. M. Mabuchi, H. Iwasaki, K. Yanase, K. Higash, 'Low temperature superplasticity in an AZ91 magnesium alloy produced by ECAE' Scripta Mater., Vol. 36, No. 6, pp. 681-686, 1997 https://doi.org/10.1016/S1359-6462(96)00444-7
  13. S.K. Jha, K.S. Ravichandran, 'Effect of mean stress (stress ratio) and aging on fatigue-crack growth in a metastable beta titanium alloy' Met. & Mater. Trans. A, Vol.3 1A, pp. 703-714, 2000
  14. S.R. Agnew, A. Vinogradov, S. Hashimoto, J.R.. Weertman, 'Overview of fatigue performance of Cu processed by severe plastic deformation', J. Electronic. Mater. Vol. 28, No. 9, pp. 1038-1044, 1999 https://doi.org/10.1007/s11664-999-0181-0