Recrystallization in AZ31 Magnesium Alloy during Hot Deformation

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Abstract:

In this study, isothermal torsion tests were carried out on magnesium AZ31B alloy under constant strain rate conditions, in the range of 250 to 400oC at 0.01, 0.1, and 1.0 s-1. Alloy flow stress dependence on strain rate and temperature can be described by a power law with activation energy of 130 kJ/mol. Microstructural examination of hot deformed samples shows very fine recrystallized grains decorating grain boundaries of larger gains in the form of a necklace. These fine grains are produced by dynamic recrystallization at the grain boundaries of original grains. Microstructure evolution, based on samples quenched at different strain levels, indicates that increasing deformation strain has little effect on recrystallized grain size but widens the recrystallized region, with full recrystallization achieved at a certain high strain level. Recrystallized grain size increases with increasing deformation temperature and strain rate. The latter suggests recrystallization in AZ31 to be essentially a time dependant phenomenon.

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Periodical:

Materials Science Forum (Volumes 475-479)

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559-562

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Online since:

January 2005

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© 2005 Trans Tech Publications Ltd. All Rights Reserved

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[1] A. G. Beer and M. R. Barnett, The Hot Working Flow Stress and Microstructure in Magnesium AZ31, Magnesium Technology 2002, TMS (2002), pp.193-198.

DOI: 10.1002/9781118859803.ch59

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[2] A. Mwembela and H. J. McQueen, Hot Workability of Magnesium Alloy ZK60, Hot Workability of Steels and Light Alloys-Composites (1996), pp.181-188.

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[3] A. Mwembela, E. B. Konopleva and H. J. McQueen, Microstructural Development in Mg Alloy AZ31 During Hot Working, Scripta Materialia, Vol 37, No. 11 (1997), pp.1789-1795.

DOI: 10.1016/s1359-6462(97)00344-8

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[4] W. J. Liu, V. Kao, E. Essadiqi, A. Elwazri, S. Yue and R. Verma, Dynamic Recrystallization of AZ31 Magnesium Alloy During Torsion Deformation at Elevated Temperatures, Magnesium Technology 2004, pp.73-78, TMS (2004). 4.

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