Room temperature creep and substructure formation in pure aluminum at ultra-low strain rates

J. J. Shen, K. Ikeda, Satoshi Hata, Hideharu Nakashima

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

The creep behavior in pure aluminum has been investigated by helicoid spring creep tests at strain rates, ε, lower than 10-10 s -1 and room temperature, 298 K. It was found that the creep behavior at the very low ε depends strongly on grain sizes and impurity concentrations: in high-purity aluminum (5 N Al) with an average grain size of 24 μm, the stress exponent was n ∼ 1; while, when the average grain size was larger than 1600 μm, the stress exponent was n ∼ 5. Microstructural observation shows the formation of large dislocation cells, 10 μm. On the other hand, in commercial low-purity aluminum (2 N Al) with the average grain size of 25 μm, the stress exponent was n = 2. Microstructural observations revealed dislocations emitted from grain boundaries and the formation of lattice dislocation cells. To evaluate creep deformation mechanisms of the pure aluminum, stress change tests were conducted during creep tests. It was revealed that the deformation in the range of the stress exponent, n ∼ 5, was controlled by recovery driven by internal stress, σi, because instantaneous strains at stress increment were larger than that at stress reduction. While the deformation behaviors in the ranges of the stress exponents, n ∼ 1 and n = 2, were in viscous manner, because instantaneous strains at stress increment and reduction were in the same level. Based on those experimental results, the creep mechanisms have been discussed.

Original languageEnglish
Title of host publicationTMS 2011 - 140th Annual Meeting and Exhibition, Supplemental Proceedings
Pages585-592
Number of pages8
Volume2
Publication statusPublished - 2011
EventTMS 2011 - 140th Annual Meeting and Exhibition - San Diego, CA, United States
Duration: Feb 27 2011Mar 3 2011

Other

OtherTMS 2011 - 140th Annual Meeting and Exhibition
CountryUnited States
CitySan Diego, CA
Period2/27/113/3/11

Fingerprint

substructures
Aluminum
strain rate
Strain rate
Creep
aluminum
room temperature
exponents
grain size
Temperature
creep tests
Dislocations (crystals)
purity
cells
Crystal lattices
residual stress
Residual stresses
Grain boundaries
grain boundaries
recovery

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys

Cite this

Shen, J. J., Ikeda, K., Hata, S., & Nakashima, H. (2011). Room temperature creep and substructure formation in pure aluminum at ultra-low strain rates. In TMS 2011 - 140th Annual Meeting and Exhibition, Supplemental Proceedings (Vol. 2, pp. 585-592)

Room temperature creep and substructure formation in pure aluminum at ultra-low strain rates. / Shen, J. J.; Ikeda, K.; Hata, Satoshi; Nakashima, Hideharu.

TMS 2011 - 140th Annual Meeting and Exhibition, Supplemental Proceedings. Vol. 2 2011. p. 585-592.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Shen, JJ, Ikeda, K, Hata, S & Nakashima, H 2011, Room temperature creep and substructure formation in pure aluminum at ultra-low strain rates. in TMS 2011 - 140th Annual Meeting and Exhibition, Supplemental Proceedings. vol. 2, pp. 585-592, TMS 2011 - 140th Annual Meeting and Exhibition, San Diego, CA, United States, 2/27/11.
Shen JJ, Ikeda K, Hata S, Nakashima H. Room temperature creep and substructure formation in pure aluminum at ultra-low strain rates. In TMS 2011 - 140th Annual Meeting and Exhibition, Supplemental Proceedings. Vol. 2. 2011. p. 585-592
Shen, J. J. ; Ikeda, K. ; Hata, Satoshi ; Nakashima, Hideharu. / Room temperature creep and substructure formation in pure aluminum at ultra-low strain rates. TMS 2011 - 140th Annual Meeting and Exhibition, Supplemental Proceedings. Vol. 2 2011. pp. 585-592
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