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Low-Temperature Creep at Ultra-Low Strain Rates in Pure Aluminum Studied by a Helicoid Spring Specimen Technique
| Title: | Low-Temperature Creep at Ultra-Low Strain Rates in Pure Aluminum Studied by a Helicoid Spring Specimen Technique |
| Authors: | Shen, Junjie Browse this author | | Yamasaki, Shigeto Browse this author | | Ikeda, Ken-ichi Browse this author →KAKEN DB | | Hata, Satoshi Browse this author | | Nakashima, Hideharu Browse this author |
| Keywords: | pure aluminum | | dislocation | | ultra-low strain rate | | helicoid spring creep test | | grain boundary | | stress exponent |
| Issue Date: | 1-Jul-2011 |
| Publisher: | The Japan Institute of Metals |
| Journal Title: | MATERIALS TRANSACTIONS |
| Volume: | 52 |
| Issue: | 7 |
| Start Page: | 1381 |
| End Page: | 1387 |
| Publisher DOI: | 10.2320/matertrans.M2010405 |
| Abstract: | The creep behavior in pure aluminum has been investigated by helicoid spring creep tests at strain rates, \\dotε, lower than 10−10 s−1 and low temperature ranging from 0.32Tm to 0.43Tm. It was found that the creep behavior in this region depends strongly on grain sizes and impurity concentrations. For high-purity aluminum (5 N Al) with an average grain size, dg>1600 μm, nearly the wire diameter of the spring sample, where the role of grain boundary during creep deformation can be negligible, the stress exponent was n∼5 and the activation energy was Qc=32 kJ/mol. Microstructural observation showed the formation of large dislocation cells (∼10 μm) and tangled dislocations at the cell walls. For high-purity aluminum (5 N Al) with dg=24 μm, the stress exponent was n∼1 and the activation energy was Qc=15 kJ/mol. On the other hand, for commercial low-purity aluminum (2 N Al) with dg=25 μm, the stress exponent was n=2 and the activation energy was Qc=25 kJ/mol. Microstructural observations revealed dislocations emitted from grain boundaries, those dislocations interacting with intragranular dislocations and the formation of dislocation cells in the grains. Based on those experimental results, the low-temperature creep mechanisms in pure aluminum at \\dotε<10−10 s−1 have been discussed. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/75556 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 池田 賢一
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