Abstract
The behavior of extruded Mg–Gd–Al–Zn magnesium alloys at elevated temperatures was studied to elucidate the effect of intermetallic compounds on thermal stability, grain coarsening mode, and grain growth kinetics. The presence of the fine and widely distributed intermetallic (Mg,Al)3Gd phase in the extruded microstructure of the Mg–4.8Gd–1.2Al–1Zn alloy was found to be quite effective in inhibiting grain growth. This was not the case for the Mg–3Gd–3Al–1Zn alloy, where the extruded microstructure showed that the grain boundaries are not effectively pinned by the main Al2Gd intermetallic phase. The grain coarsening situation was found to be more severe for the Mg–6Al–1Zn alloy because no second phases were present to pin the grain boundaries at elevated temperatures. The simultaneous presence of Al and Gd was found to be helpful in increasing the solidus temperature, and in this way, it further contributes to increasing thermal stability of the magnesium alloys. The abnormal grain growth occurred by penetrating into grain boundaries of smaller grains and by the formation of discrete islands inside large abnormal grains, which provided evidence for the occurrence of the solid-state wetting mechanism in this magnesium alloy.
Similar content being viewed by others
References
B.L. Mordike and T. Ebert: Magnesium properties—Applications—Potential. Mater. Sci. Eng., A 302, 37 (2001).
S. Nayak, B. Bhushan, R. Jayaganthan, P. Gopinath, R.D. Agarwal, and D. Lahiri: Strengthening of Mg based alloy through grain refinement for orthopaedic application. J. Mech. Behav. Biomed. Mater. Res. 59, 57 (2016).
Y. Ali, D. Qiu, B. Jiang, F. Pan, and M. Zhang: Current research progress in grain refinement of cast magnesium alloys: A review article. J. Alloys Compd. 61, 639 (2015).
M.K. Kulekci: Magnesium and its alloys applications in automotive industry. Int. J. Adv. Manuf. Technol. 39, 851 (2008).
M. Kawasaki and T.G. Langdon: Review: Achieving superplastic properties in ultrafine-grained materials at high temperatures. J. Mater. Sci. 51, 19 (2016).
B. Pourbahari, H. Mirzadeh, and M. Emamy: Toward unraveling the effects of intermetallic compounds on the microstructure and mechanical properties of Mg–Gd–Al–Zn magnesium alloys in the as-cast, homogenized, and extruded conditions. Mater. Sci. Eng., A 680, 39 (2017).
D.H. St John, M. Qian, M.A. Eason, P. Cao, and Z. Hildebrand: Grain refinement of magnesium alloys. Metall. Mater. Trans. A 36, 1669 (2005).
D. Yu, D. Zhang, J. Sun, Y. Luo, H. Zhang, F. Pan, and J. Xu: Improving mechanical properties of ZM61 magnesium alloy by aging before extrusion. J. Alloys Compd. 690, 553 (2017).
A. Kumar, G. Kumar Meenashisundaram, V. Manakari, G. Parande, and M. Gupta: Lanthanum effect on improving CTE, damping, hardness and tensile response of Mg–3Al alloy. J. Alloys Compd. 695, 3612 (2017).
L. Zhang, W. Chen, W. Zhang, W. Wang, and E. Wang: Microstructure and mechanical properties of thin ZK61 magnesium alloy sheets by extrusion and multi-pass rolling with lowered temperature. J. Mater. Process. Technol. 237, 65 (2016).
D. Vinotha, K. Raghukandan, U.T.S. Pillai, and B.C. Pai: Grain refining mechanisms in magnesium alloys—An overview. Trans. Indian Inst. Met. 62, 521 (2009).
Q. Miao, L. Hu, X. Wang, and E. Wang: Grain growth kinetics of a fine-grained AZ31 magnesium alloy produced by hot rolling. J. Alloys Compd. 493, 87 (2010).
X. Wang, L. Hu, K. Liu, and Y. Zhang: Grain growth kinetics of bulk AZ31 magnesium alloy by hot pressing. J. Alloys Compd. 527, 193 (2012).
J.J. Bhattacharyya, S.R. Agnew, and G. Muralidharan: Texture enhancement during grain growth of magnesium alloy AZ31B. Acta Mater. 86, 80 (2015).
J.P. Young, H. Askari, Y. Hovanski, M.J. Heiden, and D.P. Field: Thermal microstructural stability of AZ31 magnesium after severe plastic deformation. Mater. Charact. 101, 9 (2015).
M. Roostaei, M. Shirdel, M.H. Parsa, R. Mahmudi, and H. Mirzadeh: Microstructural evolution and grain growth kinetics of GZ31 magnesium alloy. Mater. Charact. 118, 584 (2016).
C.W. Su, L. Lu, and M.O. Lai: Recrystallization and grain growth of deformed magnesium alloy. Philos. Mag. 88, 181 (2008).
R. Alizadeh, R. Mahmudi, A.H.W. Ngan, and T.G. Langdon: Microstructural stability and grain growth kinetics in an extruded fine-grained Mg–Gd–Y–Zr alloy. J. Mater. Sci. 50, 4940 (2015).
C.J. Silva, A. Kula, R.K. Mishra, and M. Niewczas: Grain growth kinetics and annealed texture characteristics of Mg–Sc binary alloys. J. Alloys Compd. 687, 548 (2016).
F.J. Humphreys and M. Hatherly: Recrystallization and Related Annealing Phenomena, 2nd ed. (Elsevier, Oxford, U.K., 2004).
B. Verlinden, J. Driver, I. Samajdar, and R.D. Doherty: Thermo-mechanical Processing of Metallic Materials, 1st ed. (Elsevier, Amsterdam, The Netherlands, 2007).
J. Rudnizki, B. Zeislmair, U. Prahl, and W. Bleck: Prediction of abnormal grain growth during high temperature treatment. Comput. Mater. Sci. 49, 209 (2010).
S.H. Jung, D.Y. Yoon, and S.J.L. Kang: Mechanism of abnormal grain growth in ultrafine-grained nickel. Acta Mater. 61, 5693 (2013).
M. Shirdel, H. Mirzadeh, and M.H. Parsa: Abnormal grain growth in AISI 304L stainless steel. Mater. Charact. 97, 11 (2014).
M. Naghizadeh and H. Mirzadeh: Elucidating the effect of alloying elements on the behavior of austenitic stainless steels at elevated temperatures. Metall. Mater. Trans. A 47, 5698 (2016).
V.Y. Novikov: Diagram of grain growth modes. Mater. Lett. 185, 436 (2016).
P.R. Rios: Abnormal grain growth development from uniform grain size distributions. Acta Mater. 45, 1785 (1997).
J.S. Choi and D.Y. Yoon: The temperature dependence of abnormal grain growth and grain boundary faceting in 316L stainless steel. ISIJ Int. 41, 478 (2001).
M. Shirdel, H. Mirzadeh, and M.H. Parsa: Microstructural evolution during normal/abnormal grain growth in austenitic stainless steel. Metall. Mater. Trans. A 45, 5185 (2014).
K.J. Ko, P.R. Cha, D. Srolovitz, and N.M. Hwang: Abnormal grain growth induced by sub-boundary-enhanced solid-state wetting: Analysis by phase-field model simulations. Acta Mater. 57, 838 (2009).
X. Wang, W. Du, K. Liu, Z. Wang, and Sh. Li: Microstructure, tensile properties and creep behaviors of as-cast Mg–2Al–1Zn–xGd (x = 1, 2, 3, and 4 wt%) alloys. J. Alloys Compd. 522, 78 (2012).
F. Bu, Q. Yang, K. Guan, X. Qiu, D. Zhang, T. Zheng, X. Cui, Sh. Sun, Z. Tang, W. Sun, X. Liu, and J. Meng: Study on the mutual effect of La and Gd on microstructure and mechanical properties of Mg–Al–Zn extruded alloy. J. Alloys Compd. 688, 1241 (2016).
B. Pourbahari, M. Emamy, and H. Mirzadeh: Synergistic effect of Al and Gd on enhancement of mechanical properties of magnesium alloys. Prog. Nat. Sci.: Mater. Int. 27, 228 (2017).
ASTM E112-13: Standard Test Methods for Determining Average Grain Size (ASTM International, West Conshohocken, PA, 2013). Available at: www.astm.org (accessed September 2017).
A.H. Feng and Z.Y. Ma: Enhanced mechanical properties of Mg–Al–Zn cast alloy via friction stir processing. Scr. Mater. 56, 397 (2007).
X.U. Yan, L.X. Hu, S.U.N. Yu, J.B. Jia, and J.F. Jiang: Microstructure and mechanical properties of AZ61 magnesium alloy prepared by repetitive upsetting-extrusion. Trans. Nonferrous Met. Soc. China 25, 381 (2015).
N.M. Hwang: Simulation of the effect of anisotropic grain boundary mobility and energy on abnormal grain growth. J. Mater. Sci. 33, 5625 (1998).
A.D. Rollett, D.J. Srolovitz, and M.P. Anderson: Simulation and theory of abnormal grain growth—Anisotropic grain boundary energies and mobilities. Acta Metall. 37, 1227 (1989).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Pourbahari, B., Mirzadeh, H. & Emamy, M. Elucidating the effect of intermetallic compounds on the behavior of Mg–Gd–Al–Zn magnesium alloys at elevated temperatures. Journal of Materials Research 32, 4186–4195 (2017). https://doi.org/10.1557/jmr.2017.415
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1557/jmr.2017.415