Two series ingots of Mg69+xZn30-xY1 and Mg68+xZn30-xY2 (x = 0, 3 and 6, atomic percent) alloys with the diameter of 100 mm were obtained by ordinary gravity casting, respectively. The phase compositions and microstructures were investigated by means of optical microscope (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The law that the number, morphology, size and distribution of the quasicrystal phase varied with the content of Zn and Y was discussed. The results showed that the microstructures of the two series alloys were composed of MgZn matrix, Mg30Zn60Y10 quasicrystal phase (I) and α-Mg phase. The I-phase directly nucleated and grew during the cooling process of Mg–Zn–Y melt. The morphology of the two series alloys was different obviously. The I-phase exhibited small pentagonal or five-petal shape and six-petal shape in the microstructure of the Mg69+xZn30-xY1 alloy, while it was not regular polygon shape in the microstructure of the Mg68+xZn30-xY2 alloy. At the same time, with decreasing Zn content, the granularity and homogenization degree of the quasicrystals enhanced gradually. The quasicrystals increased and distributed more evenly.
This is a preview of subscription content, log in to check access.
This work was supported by Natural Science Foundation of Guangdong Province (2016A030313802), Project on Scientific Research of Guangzhou City (201707010393) and Technology Innovation Project of Science and Technology Small and Medium Enterprise of Guangdong Province (2016A010120024).
J.F. Nie, B.C. Muddle, Precipitation in magnesium alloy WE54 during isothermal ageing at 250 °C. Scripta Mater. 40, 1089–1094 (1999)CrossRefGoogle Scholar
C. Antion, P. Donnadieu, F. Perrard, A. Deschamps, C. Tassin, A. Pisch, Hardening precipitation in a Mg–4Y–3RE alloy. Acta Mater. 51, 5335–5348 (2003)CrossRefGoogle Scholar
D.H. Bae, M.H. Lee, K.T. Kim, W.T. Kim, D.H. Kim, Application of quasicrystalline particles as a strengthening phase in Mg–Zn–Y alloys. J. Alloys Compd. 342, 445–450 (2002)CrossRefGoogle Scholar
P.W. Stephens, A.I. Goldman, Metallic phase with long-range orientational order and no translational symmetry. Phys. Rev. Lett. 53, 1951–1954 (1984)CrossRefGoogle Scholar
J.S. Zhang, Y.Q. Zhang, Y. Zhang, C.X. Xu, X.M. Wang, J. Yan, Effect of Mg-based spherical quasicrystal on microstructures and mechanical properties of ZA54 alloy. Trans. Nonferrous Met. Soc. Chin. 20, 1199–1204 (2010)CrossRefGoogle Scholar
A.I. Goldman, Magnetism in icosahedral quasicrystals: current status and open questions. Sci. Technol. Adv. Mater. 15, 044801-1–044801-15 (2014)CrossRefGoogle Scholar
Y.L. Ju, D.H. Kim, H.K. Lim, D.H. Kim, Effects of Zn/Y ratio on microstructure and mechanical properties of Mg-Zn-Y alloys. Mater. Lett. 59, 3801–3805 (2005)CrossRefGoogle Scholar
A. Singh, M. Watanabe, A. Kato, A.P. Tsai, Crystallographic orientations and interfaces of icosahedral quasicrystalline phase growing on cubic W phase in Mg–Zn–Y alloys. Mater. Sci. Eng., A 397, 22–34 (2005)CrossRefGoogle Scholar
S. Sen, T. Mukerji, A generalized classical nucleation theory for rough interfaces: application in the analysis of homogeneous nucleation in silicate liquids. J. Non-Cryst. Solids 246, 229–239 (1999)CrossRefGoogle Scholar
F. Spaepen, A structural model for the solid-liquid interface in monatomic systems. Acta Metall. 23, 729–743 (1975)CrossRefGoogle Scholar
F. Shi, Quasicrystal Phase and Its Formation Mechanism in Ordinary Solidified Mg–Zn–Y Alloy (Xi’an University of Technology, 2003, in Chinese)Google Scholar
Z.P. Luo, S.Q. Zhang, Y.L. Tang, D.S. Zhao, On the stable quasicrystals in slowly coiled Mg-Zn-Y alloys. Scripta Metall. Mater. 32, 1411–1416 (1995)CrossRefGoogle Scholar
Y.B. Zhang, S. Yu, Y. Song, X. Zhu, Microstructures and mechanical properties of quasicrystal reinforced Mg matrix composites. J. Alloys Compd. 464, 575–579 (2008)CrossRefGoogle Scholar
H.Q. Hu, Metal Solidification Principle (China Machine Press, Beijing, 2000, in Chinese)Google Scholar