Skip to main content Accessibility help

Grain refinement of Mg–10Gd alloy by Al additions

  • Jichun Dai (a1), Mark Easton (a2), Suming Zhu (a2), Guohua Wu (a3) and Wenjiang Ding (a3)...

The addition of Al to a Mg–10Gd alloy was found to lead to substantial grain size reduction during casting at concentrations between 0.8% and 1.3%. At these concentrations, Al2Gd particles were found at the center of grains, and the orientation relationship $[112]_{{\rm{Al}}_{\rm{2}} {\rm{Gd}}} \,{\rm{‖}}\,[2\bar 1\bar 10]_{{\rm{\alpha - Mg}}} ,\,(1\bar 10)_{{\rm{Al}}_{\rm{2}} {\rm{Gd}}} \,{\rm{‖}}\,(0\bar 110)_{{\rm{\alpha - Mg}}} $ was found reproducibly between Al2Gd and α-Mg, indicating that these are the heterogeneous nucleant particles that form in situ at these Al contents. Most of these nuclei were between 2 and 7 μm in size. Furthermore, little grain coarsening was observed during solution treatment, particularly compared with an alloy grain refined by Zr particles where substantial coarsening occurred. This appears to be because Al2Gd particles restrict grain boundary motion during solution treatment.

Corresponding author
a)Address all correspondence to this author. e-mail:
Hide All
1.Pekguleryuz, M. and Celikin, M.: Creep resistance in magnesium alloys. Int. Mater. Rev. 55, 197 (2010).
2.Gao, X. and Nie, J.F.: Enhanced precipitation-hardening in Mg-Gd alloys containing Ag and Zn. Scr. Mater. 58, 619 (2008).
3.Gao, X., He, S.M., Zeng, X.Q., Peng, L.M., Ding, W.J., and Nie, J.F.: Microstructure evolution in a Mg–15Gd–0.5Zr (wt%) alloy during isothermal aging at 250 °C. Mater. Sci. Eng., A 431, 322 (2006).
4.StJohn, D.H., Qian, M., Easton, M.A., Cao, P., and Hildebrand, Z.: Grain refinement of magnesium alloys. Metall. Mater. Trans. A 36, 1669 (2005).
5.Vinotha, D., Raghukandan, K., Pillai, U., and Pa, B.: Grain refining mechanisms in magnesium alloys – An overview. Trans. Indian Inst. Met. 62, 521 (2009).
6.Kubota, K., Mabuchi, M., and Higashi, K.: Review processing and mechanical properties of fine-grained magnesium alloys. J. Mater. Sci. 34, 2255 (1999).
7.Bettles, C.J., Gibson, M.A., and Zhu, S.M.: Microstructure and mechanical behavior of an elevated temperature Mg-rare earth based alloy. Mater. Sci. Eng., A 505, 6 (2009).
8.Qian, M., StJohn, D.H., and Frost, M.T.: Heterogeneous nuclei size in magnesium–zirconium alloys. Scr. Mater. 50, 1115 (2004).
9.Qian, M., Hildebrand, Z.C.G., and StJohn, D.H.: The loss of dissolved zirconium in zirconium-refined magnesium alloys after remelting. Metall. Mater. Trans. A 40, 2470 (2009).
10.Qian, M., Zheng, L., Graham, D., Frost, M.T., and StJohn, D.H.: Settling of undissolved zirconium particles in pure magnesium melts. J. Light Met. 1, 157 (2001).
11.Jie, L.K., An, L.Q., Tian, J.X., Jun, C., Yuan, Z.X., and Qing, Z.: Effects of Sm addition on microstructure and mechanical properties of Mg–6Al–0.6Zn alloy. Scr. Mater. 60, 1101 (2009).
12.Qiu, D., Zhang, M.X., Taylor, J.A., and Kelly, P.M.: A new approach to designing a grain refiner for Mg casting alloys and its use in Mg–Y-based alloys. Acta Mater. 57, 3052 (2009).
13.Li, W.P., Zhou, H., and Li, Z.F.: Effect of gadolinium on microstructure and rolling capability of AZ31 alloy. J. Alloys Compd. 475, 227 (2009).
14.Wang, X., Du, W., Liu, K., Wang, Z., and Li, S.: 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).
15.He, S.M., Zeng, X.Q., Peng, L.M., Gao, X., Nie, J.F., and Ding, W.J.: Microstructure and strengthening mechanism of high strength Mg–10Gd–2Y–0.5Zr alloy. J. Alloys Compd. 427, 316 (2007).
16.Sun, M., Wu, G.H., Wang, W., and Ding, W.J.: Effect of Zr on the microstructure, mechanical properties and corrosion resistance of Mg–10Gd–3Y magnesium alloy. Mater. Sci. Eng., A 523, 145 (2009).
17.Zheng, K.Y., Dong, J., Zeng, X.Q., and Ding, W.J.: Precipitation and its effect on the mechanical properties of a cast Mg–Gd–Nd–Zr alloy. Mater. Sci. Eng., A 489, 44 (2008).
18.Peng, Q.M., Wu, Y.M., Fang, D.Q., Meng, J., and Wang, L.M.: Microstructures and properties of Mg–7Gd alloy containing Y. J. Alloys Compd. 430, 252 (2007).
19.Villars, P. and Calvert, L.D.: Pearson’s Handbook of Crystallographic Data for Intermetallic Phases, 2nd ed. (ASM International, Materials Park, OH, 1991); pp. 855, 4291.
20.Peng, Q., Huang, Y., Meng, J., Li, Y., and Kainer, K.U.: Strain induced GdH2 precipitate in Mg–Gd based alloys. Intermetallics 19, 382 (2011).
21.Qiu, D. and Zhang, M.X.: Effect of active heterogeneous nucleation particles on the grain refining efficiency in an Mg–10wt% Y cast alloy. J. Alloys Compd. 488, 260 (2009).
22.Crossley, F.A. and Mondolfo, L.F.: Mechanism of grain refinement in aluminum alloys. Trans. AIME. 191, 1143 (1951).
23.StJohn, D.H., Cao, P., Qian, M., and Easton, M.A.: A new analytical approach to reveal the mechanisms of grain refinement. Adv. Eng. Mater. 9, 739 (2007).
24.Zhang, M.X., Kelly, P.M., Qian, M., and Taylor, J.A.: Crystallography of grain refinement in Mg–Al based alloys. Acta Mater. 53, 3261 (2005).
25.Qiu, D., Zhang, M.X., Fu, H.M., Kelly, P.M., and Taylor, J.A.: Crystallography of recently developed grain refiners for Mg–Al alloys. Philos. Mag. Lett. 87, 505 (2007).
26.Zhang, M.X. and Kelly, P.M.: Crystallography and morphology of Widmanstätten cementite in austenite. Acta Mater. 46, 4617 (1998).
27.Qiu, D., Taylor, J.A., and Zhang, M.X.: Understanding the co-poisoning effect of Zr and Ti on the grain refinement of cast aluminum alloys. Metall. Mater. Trans. A 41, 3412 (2010).
28.Qiu, D., Zhang, M.X., and Kelly, P.M.: Crystallography of heterogeneous nucleation of Mg grains on Al2Y nucleation particles in an Mg–10wt% Y alloy. Scr. Mater. 61, 312 (2009).
29.Greer, A.L., Bunn, A.M., Tronche, A., Evans, P.V., and Bristow, D.J.: Modelling of inoculation of metallic melts: Application to grain refinement of aluminum by Al–Ti–B. Acta Mater. 48, 2823 (2000).
30.Tronche, A. and Greer, A.L.: Electron back-scatter diffraction study of inoculation of Al. Philos. Mag. Lett. 81, 321 (2001).
31.Quested, T.E. and Greer, A.L.: The effect of the size distribution of inoculant particles on as-cast grain size in aluminum alloys. Acta Mater. 52, 3859 (2004).
32.Qian, M.: Heterogeneous nucleation on potent spherical substrates during solidification. Acta Mater. 55, 943 (2007).
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Materials Research
  • ISSN: 0884-2914
  • EISSN: 2044-5326
  • URL: /core/journals/journal-of-materials-research
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed