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Vol.37, No.3, 273 ~ 281, 1999
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| Title |
| Research Paper / Mechanical Behavior : Effect on Thermomechanical Processing and Solution Strengthenig on the Superplasticity of an Al - Mg - Cr alloy |
| 정병선Byung Sun Chung, 맹덕영Duck Young Maeng, 전계풍Jifeng Tian, 홍순익Sun Ig Hong, 이병훈Byung Hoon Lee |
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| Abstract |
| The effect of transition elements and thermomechanical processing(TMP) on the superplastic behavior of Al-7%Mg-0.3%Cr alloys were examined and correlated to the microstructural evolution during superplastic deformation. To establish an optimum manufacturing process for the enhanced superplastic properties, different processing methods such as warm rolling and cold rolling were used. In cold rolled Al-7%Mg-0.3%Cr alloys with intermediate annealing. the maximum elongation (close to 730%) was observed at 530℃. On the other hand, low temperature superplasticity was not observed in Al-7%Mg-0.3%Cr alloys with the TMP developed by McNelley because of the suppression of continuous recrystallization due to the dispersion of intermetallics. However, when these TMPed Al alloys were tested at high enough temperatures above the recrystallization temperature, the maximum elongation reached approximately 400% In this study, the possible effect of solute-dislocation interaction on the high temperature ductility was also examined. The predicted strain rate range of high ductility associated with high strain rate sensitivity due to solute strengthening coincides with the range of high temperature superplasticity of Al-Mg alloys, suggesting solute strengthening may be contributory to high temperature superplasticity of Al-Mg alloy. |
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