The Effect of Reversed Loading Conditions on the Mechanical Behaviour of Extruded Magnesium Alloy AZ31

• Authors: J. Bohlen , P. Dobron , L. Nascimento , K. Parfenenko , F. Chmelik , D. Letzig
• Languages of publication: EN

Abstracts

EN

An indirectly extruded round bar of magnesium alloy AZ31 has been subjected to a cyclic test consisting of preloading in compression to different values of maximum stress followed by a single tensile test segment. Concurrent acoustic emission measurements were used to determine the active deformation mechanisms during plastic flow and work hardening. Electron backscattering diffraction was applied to obtain local orientation images in order to reveal twins and twinned fractions of the microstructure. Twins form preferentially in larger grains during the compression test segment and only with increasing stress do smaller grains show twinning. Some grains are completely re-oriented as a result of twinning. During the tensile test segment, untwinning is the most significant deformation mechanism although in some re-oriented grains new twins also nucleate. The acoustic emission count rates confirm that this is only the case after compression to higher stress levels.

Keywords

EN

43.40.Le; 61.72.Mm; 81.05.Bx; 81.70.Bt

Discipline

• 61.72.Mm: Grain and twin boundaries
• 81.05.Bx: Metals, semimetals, and alloys
• 81.70.Bt: Mechanical testing, impact tests, static and dynamic loads(see also 62.20.M- Structural failure of materials; 46.50.+a Fracture mechanics, fatigue, and cracks)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2012
• Volume: 122
• Issue: 3
• Pages: 444-449

Dates

published

2012-09

Contributors

author

J. Bohlen

• Magnesium Innovation Centre, Helmholtz-Zentrum Geesthacht, D21502 Geesthacht, Germany

author

P. Dobron

• Department of Physics of Materials, Charles University, Ke Karlovu 5, CZ 121 16 Prague 2, Czech Republic

author

L. Nascimento

• Magnesium Innovation Centre, Helmholtz-Zentrum Geesthacht, D21502 Geesthacht, Germany

author

K. Parfenenko

• Department of Physics of Materials, Charles University, Ke Karlovu 5, CZ 121 16 Prague 2, Czech Republic

author

F. Chmelik

• Department of Physics of Materials, Charles University, Ke Karlovu 5, CZ 121 16 Prague 2, Czech Republic

author

D. Letzig

• Magnesium Innovation Centre, Helmholtz-Zentrum Geesthacht, D21502 Geesthacht, Germany

References

• [1] M.R. Barnett, Z. Keshavarz, A.G. Beer, D. Atwell, Acta Mater. 52, 5093 (2004)
• [2] C.H.J. Davies, S. Yi, J. Bohlen, K.U. Kainer, H.G. Brokmeier, Mater. Sci. Forum 495-497, 1633 (2005)
• [3] J. Bohlen, S.B. Yi, J. Swiostek, D. Letzig, H.G. Brokmeier, K.U. Kainer, Scr. Mater. 53, 259 (2005)
• [4] Y.N. Wang, J.C. Huang, Acta Mater. 55, 897 (2007)
• [5] X.Y. Lou, M. Li, R.K. Boger, S.R. Agnew, R.H. Wagoner, Int. J. Plasticity 23, 44 (2007)
• [6] P.G. Partridge, Metall. Rev. 118, 169 (1967)
• [7] J. Bohlen, P. Dobroň, J. Swiostek, D. Letzig, F. Chmelík, P. Lukáč, K.U. Kainer, Mater. Sci. Eng. A 462, 302 (2007)
• [8] M.A. Meyers, O. Vohringer, V.A. Lubarda, Acta Mater. 49, 4025 (2001)
• [9] P. Dobroň, F. Chmelík, S. Yi, K. Parfenenko, D. Letzig, J. Bohlen, Scr. Mater. 65, 424 (2011)
• [10] L. Nascimento, L. Fuskova, J. Bohlen, D. Letzig, K.U. Kainer, in: Proc. 8th Int. Conf. on Magnesium Alloys and Their Applications, Weimar, Elsevier, Weinheim 2010, p. 639
• [11] C.R. Heiple, S.H. Carpenter, J. Acoustic Emission 6, 177 (1987)
• [12] J. Bohlen, P. Dobroň, J. Swiostek, D. Letzig, F. Chmelík, P. Lukáč, K.U. Kainer, Mater. Sci. Eng. A 462, 307 (2007)
• [13] Standard Practice for Acoustic Emission Examination of Fibre Glass Reinforced Plastic Resin, ASTM E 1067-85, Tank/Vessels, May 31, 1985
• [14] J. Bohlen, F. Chmelík, P. Dobroň, D. Letzig, F. Kaiser, P. Lukáč, K.U. Kainer, J. Alloys Comp. 378, 214 (2004)
• [15] I.L. Dillamore, W.T. Roberts, Metall. Rev. 10, 271 (1965)
• [16] E.W. Kelly, W.F. Hosford, Trans. Metall. Soc. AIME 242, 5 (1968)
• [17] R.E. Reed Hill, R. Abbaschian, Physical Metallurgy Principles, PWS Publ. Company, Boston 1994
• [18] S. Kleiner, P.J. Uggowitzer, Mater. Sci. Eng. A 379, 258 (2004)
• [19] M.A. Gharghouri, G.C. Weatherly, J.D. Embury, J. Root, Philos. Mag. A 79, 1671 (1999)

Identifiers

DOI

10.12693/APhysPolA.122.444