Abstract
Quaternary eutectic presents far more complexity than binary and ternary eutectics, and its understanding can offer fundamental knowledge of the microstructure formation in a multi-component system. Accurate characterization of the quaternary eutectic structure can provide experimental evidence to validate simulation models for the multi-phase solidification. In this study, a quaternary eutectic alloy with a composition of Al-16.74 Cu-40.54 Ag-6.46 Mg in wt% was directly solidified with a velocity of 0.4 μm/s in a vertical type Bridgeman furnace. The composition of the constituent phases in the quaternary eutectic was determined by electron probe micro-analyzer, and their crystal structures were examined by x-ray diffraction. The quaternary eutectic is composed of α-Al, θ-Al2Cu, AgAlMg, and a new intermetallic phase considered as Ag5Mg3Al2. The morphology of the eutectic phases, and their spatial distribution were studied in 3D by a serial sectioning technique combined with the focused ion beam. The quaternary eutectic exhibits regular rod-like or fibrous morphology despite of the intermetallic nature of its three eutectic phases. Both the rod splitting and merging were observed common for all the eutectic phases in the 3D analysis, while only the rod splitting can be determined in the 2D analysis. Interconnected complex structures of split and merged rods of the AgAlMg and Ag5Mg3Al2 phases were observed in the 3D structure. Their formation is attributed to the higher tendency of the AgAlMg and Ag5Mg3Al2 phases to split and branch to compete for the Ag and Mg elements. The phase fractions of the eutectic phases were determined in both 2D and 3D, and it is concluded that the 3D measurement gives relatively better result.
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References
R. Elliott, Eutectic Solidification Processing Crystalline and Glassy Alloys (Butterworths, Guilford, 1983)
M. McLean, Directionally Solidified Materials for High Temperature Service (The Metal Society Book, London, 1983)
D.M. Stefanescu, G.J. Abbaschian, R.J. Bayuzick, Solidification Processing of Eutectic Alloys (A Publication of the Metallurgical Society, Ohio, 1988)
M.C. Flemings, Solidification Processing (Mc Graw Hill, NewYork, 1974)
W. Kurz, D.J. Fisher, Dendrite growth in eutectic alloys: the coupled zone. Int. Mater. Rev. 24(1), 177–204 (1979)
U. Hecht et al., Multiphase solidification in multicomponent alloys. Mater. Sci. Eng. R Rep. 46(1–2), 1–49 (2004)
D.J. Fisher, W. Kurz, Novel morphology of Pb/Sn/Cd/Zn quaternary eutectic. Metall. Trans. 5(6), 1508–1510 (1974)
D.J.S. Cooksey, A. Hellawel, Microstructures of ternary eutectic alloys in sytems Cd-Sn-(pb, In, Tl), Al-Cu-(mg, Zn, Ag) and Zn-Sn-Pb. J. Inst. Met. 95, 183–187 (1967)
C.R. Hutchinson et al., On the origin of the high coarsening resistance of omega plates in Al-Cu-Mg-Ag alloys. Acta Mater. 49(14), 2827–2841 (2001)
R.N. Lumley, A.J. Morton, I.J. Polmear, Enhanced creep performance in an Al-Cu-Mg-Ag alloy through underageing. Acta Mater. 50(14), 3597–3608 (2002)
R. Ferragut et al., Vacancy-solute interactions during multiple-step ageing of an Al-Cu-Mg-Ag alloy. Scr. Mater. 60(3), 137–140 (2009)
I.J. Polmear et al., After Concorde: evaluation of creep resistant Al-Cu-Mg-Ag alloys. Mater. Sci. Technol. 15(8), 861–868 (1999)
B.M. Gable et al., Assessment of the aluminum-rich corner of the Al-Cu-Mg-(Ag) phase diagram. Calphad 32(2), 256–267 (2008)
B. Zhou, L. Froyen, Microstructure development in Al-Cu-Ag-Mg quaternary alloy. IOP Conf. Ser. Mater. Sci. Eng. 27(1), 012031 (2012)
H. Singh et al., Reconstruction and quantitative characterization of multiphase, multiscale three-dimensional microstructure of a cast Al-Si base alloy. Metall. Mater. Trans. B 40(6), 859–870 (2009)
E.N. Landis, D.T. Keane, X-ray microtomography. Mater. Charact. 61(12), 1305–1316 (2010)
R.J. Contieri et al., Growth and three-dimensional analysis of a Nb-Al-Ni ternary eutectic. Mater. Charact. 59(6), 693–699 (2008)
H. Singh, A.M. Gokhale, Visualization of three-dimensional microstructures. Mater. Charact. 54(1), 21–29 (2005)
A.J. Bushby et al., Imaging three-dimensional tissue architectures by focused ion beam scanning electron microscopy. Nat. Protoc. 6(6), 845–858 (2011)
http://www.skyscan.be. Accessed 01 Nov 2013
J. De Wilde, et al., Unconstrained growth along a ternary eutectic solidification path in Al-Cu-Ag: preparation of a MAXUS sounding rocket experiment. Mater. Sci. Eng. A 413–414, 514–520 (2005)
R. Hamar, C. Lemaignan, Faceting behavior of Al2Cu during solidification. J. Cryst. Growth 53(3), 586–590 (1981)
V.V. Podolinsky, Y.N. Taran, Influence of adsorption on structure formation in eutectic systems. J. Cryst. Growth 52(4), 82–87 (1981)
M.S.S. Lim, J.E. Tibballs, P.L. Rossiter, An assessment of thermodynamic equilibria in the Ag-Al-Cu-Mg quaternary system in relation to precipitation reactions. Zeitschrift Fur Metallkunde 88(3), 236–245 (1997)
http://www.mediacy.com/index.aspx?page=ImageProPremierApps. Accessed 01 Nov 2013
Acknowledgment
This research work is supported by Belgian Science Policy Office (BELSPO) under grant of PRODEX within the frame of European Space Agency, research program SETA 2 (Solidification along a Eutectic path in Ternary Alloys).
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Zhou, B., Froyen, L. Combined Two- and Three-Dimensional (2D and 3D) Characterization of Directionally Solidified Al-Cu-Ag-Mg Quaternary Eutectic. Metallogr. Microstruct. Anal. 3, 164–173 (2014). https://doi.org/10.1007/s13632-014-0129-5
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DOI: https://doi.org/10.1007/s13632-014-0129-5