Microstructure and phase transformation of forged Mg–3.7Zn–0.3Y–0.3Gd quasicrystal alloy


An alloy with the composition of Mg–3.7Zn–0.3Y–0.3Gd (in at.%) which contains quasicrystal phase was studied by multiple means. The as-cast alloy has dendritic structure and consists of α-Mg, I-phase, W-phase, and Mg–Zn precipitations. The alloy was forged one pass and annealed at 440 °C for 4 h, then followed by two passes of compressions. Eutectics were crushed and partially dissolved after deformation and annealing. The tensile strength increased after each forge pass. Submicron scale particles precipitated all around the grains during the deformations, and the amount of precipitations was proportional to the amount of deformations. These precipitated particles were observed by high resolution transmission electron microscopy (TEM). The existence of rhomboid W’-phase with face center cubic (FCC) structure and globular I-phase was confirmed. A quasi-periodicity lamellar phase combined with I-phase was founded, which was considered to be the transient phase between I-phase and W’-phase. This phase had orientation relationship with \(\left( {1\bar 101} \right)\) of α-Mg basis and one of the 5-fold planar of the I-phase.

This is a preview of subscription content, access via your institution.

FIG. 1
FIG. 2
FIG. 3
FIG. 4
FIG. 5
FIG. 6
FIG. 7
FIG. 8
FIG. 9
FIG. 10
FIG. 11


  1. 1.

    T. Li, Z. Kui, X-G. Li, Z-W. Du, Y-J. Li, M-L. Ma, and G-L. Shi: Dynamic precipitation during multi-axial forging of an Mg–7Gd–5Y–1Nd–0.5Zr alloy. J. Magnesium Alloys 1 (1), 47 (2013).

    CAS  Article  Google Scholar 

  2. 2.

    J-W. Yuan, Z. Kui, X-H. Zhang, X-G. Li, T. Li, Y-J. Li, M-L. Ma, and G-L. Shi: Thermal characteristics of Mg–Zn–Mn alloys with high specific strength and high thermal conductivity. J. Alloys Compd. 578 (1), 32 (2013).

    CAS  Article  Google Scholar 

  3. 3.

    H. Hua, H. Kato, and G-Y. Yuan: The effect of nanoquasicrystals on mechanical properties of as-extruded Mg–Zn–Gd alloy. Mater. Lett. 79 (1), 281 (2012).

    Google Scholar 

  4. 4.

    A. Singh, M. Watanabe, and A. Kato: Microstructure and strength of quasicrystal containing extruded Mg–Zn–Y alloys for elevated temperature application. Mater. Sci. Eng., A 385 (1), 382 (2004).

    Article  Google Scholar 

  5. 5.

    Z-P. Luo and S-Q. Zhang: On the stable quasicrystals in slowly cooled Mg–Zn–Y alloys. Scr. Mater. 32 (9), 1411 (1994).

    Article  Google Scholar 

  6. 6.

    L. Yong, G-Y. Yuan, and C. Lu: Stable icosahedral phase in Mg–Zn–Gd alloy. Scr. Mater. 55 (1), 919 (2006).

    Google Scholar 

  7. 7.

    D-Q. Wan, G-C. Yang, and S-L. Chen: Growth morphology and evolution of quasicrystal in as-solidified Y-rich Mg–Zn–Y ternary alloys. Rare Met. 26 (5), 435 (2007).

    Article  Google Scholar 

  8. 8.

    G-Y. Yuan, L. Yong, and W-J. Ding: Effects of extrusion on the microstructure and mechanical properties of Mg–Zn–Gd alloy reinforced with quasicrystalline particles. Mater. Sci. Eng., A 474 (1), 348 (2008).

    Article  Google Scholar 

  9. 9.

    L. Yong, G-Y. Yuan, and W-J. Ding: Deformation behavior of Mg–Zn–Gd-based alloys reinforced with quasicrystal and Laves phases at elevated temperatures. J. Alloys Compd. 427 (1), 160 (2007).

    Google Scholar 

  10. 10.

    I.J. Kim, D.H. Bae, and D.H. Kim: Precipitates in a Mg–Zn–Y alloy reinforced by an icosahedral quasicrystalline phase. Mater. Sci. Eng., A 359 (1), 313 (2003).

    Article  Google Scholar 

  11. 11.

    W-C. Xu, X-Z. Han, and D-B. Shan: Precipitates formed in the as-forged Mg–Zn–RE alloy during ageing process at 250 °C. Mater. Charact. 75 (1), 176 (2012).

    Google Scholar 

  12. 12.

    A. Singh, W. Osawa, and H. Somekawa: Ultra-fine grain size and isotropic very high strength by direct extrusion of chill-cast Mg–Zn–Y alloys containing quasicrystal phase. Scr. Mater. 64 (1), 661 (2011).

    CAS  Article  Google Scholar 

  13. 13.

    H. Hua, T. Yuan, G-Y. Yuan, C-L. Chen, W-J. Ding, and Z-C. Wang: Formation mechanism of quasicrystals at the nanoscale during hot compression of Mg alloys. Scr. Mater. 1 (79), 61 (2014).

    Google Scholar 

  14. 14.

    G. Shao, V. Varisani, and Z. Fan: Thermodynamic modelling of the Y–Zn and Mg–Zn–Y systems. Calphad 30 (3), 286–295 (2006).

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Kui Zhang.

Additional information

Contributing Editor: Jürgen Eckert

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Yang, Y., Zhang, K., Ma, M. et al. Microstructure and phase transformation of forged Mg–3.7Zn–0.3Y–0.3Gd quasicrystal alloy. Journal of Materials Research 30, 1693–1700 (2015). https://doi.org/10.1557/jmr.2015.97

Download citation