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

Published online by Cambridge University Press:  28 April 2015

Yang Yang*
Affiliation:
States Key Lab, General Research Institute of Nonferrous Metals, Beijing 100012, China
Kui Zhang*
Affiliation:
States Key Lab, General Research Institute of Nonferrous Metals, Beijing 100012, China
Minglong Ma
Affiliation:
States Key Lab, General Research Institute of Nonferrous Metals, Beijing 100012, China
Xinggang Li
Affiliation:
States Key Lab, General Research Institute of Nonferrous Metals, Beijing 100012, China
*
a)Address all correspondence to this author. e-mail: zhkui@grinm.com
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Abstract

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.

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Articles
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Li, T., Kui, Z., Li, X-G., Du, Z-W., Li, Y-J., Ma, M-L., and Shi, G-L.: Dynamic precipitation during multi-axial forging of an Mg–7Gd–5Y–1Nd–0.5Zr alloy. J. Magnesium Alloys 1(1), 47 (2013).Google Scholar
Yuan, J-W., Kui, Z., Zhang, X-H., Li, X-G., Li, T., Li, Y-J., Ma, M-L., and Shi, G-L.: Thermal characteristics of Mg–Zn–Mn alloys with high specific strength and high thermal conductivity. J. Alloys Compd. 578(1), 32 (2013).Google Scholar
Hua, H., Kato, H., and Yuan, G-Y.: The effect of nanoquasicrystals on mechanical properties of as-extruded Mg–Zn–Gd alloy. Mater. Lett. 79(1), 281 (2012).Google Scholar
Singh, A., Watanabe, M., and Kato, A.: Microstructure and strength of quasicrystal containing extruded Mg–Zn–Y alloys for elevated temperature application. Mater. Sci. Eng., A 385(1), 382 (2004).CrossRefGoogle Scholar
Luo, Z-P. and Zhang, S-Q.: On the stable quasicrystals in slowly cooled Mg–Zn–Y alloys. Scr. Mater. 32(9), 1411 (1994).Google Scholar
Yong, L., Yuan, G-Y., and Lu, C.: Stable icosahedral phase in Mg–Zn–Gd alloy. Scr. Mater. 55(1), 919 (2006).Google Scholar
Wan, D-Q., Yang, G-C., and Chen, S-L.: Growth morphology and evolution of quasicrystal in as-solidified Y-rich Mg–Zn–Y ternary alloys. Rare Met. 26(5), 435 (2007).Google Scholar
Yuan, G-Y., Yong, L., and Ding, W-J.: 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).CrossRefGoogle Scholar
Yong, L., Yuan, G-Y., and Ding, W-J.: 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
Kim, I.J., Bae, D.H., and Kim, D.H.: Precipitates in a Mg–Zn–Y alloy reinforced by an icosahedral quasicrystalline phase. Mater. Sci. Eng., A 359(1), 313 (2003).Google Scholar
Xu, W-C., Han, X-Z., and Shan, D-B.: Precipitates formed in the as-forged Mg–Zn–RE alloy during ageing process at 250 °C. Mater. Charact. 75(1), 176 (2012).Google Scholar
Singh, A., Osawa, W., and Somekawa, H.: 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).Google Scholar
Hua, H., Yuan, T., Yuan, G-Y., Chen, C-L., Ding, W-J., and Wang, Z-C.: Formation mechanism of quasicrystals at the nanoscale during hot compression of Mg alloys. Scr. Mater. 1(79), 61 (2014).Google Scholar
Shao, G., Varisani, V., and Fan, Z.: Thermodynamic modelling of the Y–Zn and Mg–Zn–Y systems. Calphad 30(3), 286295 (2006).CrossRefGoogle Scholar