Abstract
Under the conventional solidification condition, a liquid aluminium alloy can be hardly undercooled because of oxidation. In this work, rapid solidification of an undercooled liquid Al80.4Cu13.6Si6 ternary eutectic alloy was realized by the glass fluxing method combined with recycled superheating. The relationship between superheating and undercooling was investigated at a certain cooling rate of the alloy melt. The maximum undercooling is 147 K (0.18T E). The undercooled ternary eutectic is composed of α(Al) solid solution, (Si) semiconductor and θ(CuAl2) intermetallic compound. In the (Al+Si+θ) ternary eutectic, (Si) faceted phase grows independently, while (Al) and θ non-faceted phases grow cooperatively in the lamellar mode. When undercooling is small, only (Al) solid solution forms as the leading phase. Once undercooling exceeds 73 K, (Si) phase nucleates firstly and grows as the primary phase. The alloy microstructure consists of primary (Al) dendrite, (Al+θ) pseudobinary eutectic and (Al+Si+θ) ternary eutectic at small undercooling, while at large undercooling primary (Si) block, (Al+θ) pseudobinary eutectic and (Al+Si+θ) ternary eutectic coexist. As undercooling increases, the volume fraction of primary (Al) dendrite decreases and that of primary (Si) block increases.
Similar content being viewed by others
References
Danilov D, Nestler B. Dendritic to globular morphology transition in ternary alloy solidification. Phys Rev Lett, 2004, 93: 215501
Trodahl H J, Bittar A. Amorphous thin films: Insulators, metals, and semiconductors. Adv Mater, 2001, 13: 1031–1033
Galenko P K, Danilov D A. Linear morphological stability analysis of the solid-liquid interface in rapid solidification of a binary system. Phys Rev E, 2004, 69: 051608–051621
Ruan Y, Dai F P, Wei B B. Formation of ζ phase in Cu-Ge peritectic alloys. Chin Sci Bull, 2007, 52: 2630–2635
Leonhardt M, Löser W, Lindenkreuz H G. Phase selection in undercooled peritectic Fe-Mo alloys. Acta Mater, 2002, 50: 725–734
Conti M. Curvature effects in rapid alloy solidification. Phys Rev E, 2001, 63: 041507–041514
Ovono D O, Guillot I, Massinon D. The microstructure and precipitation kinetics of a cast aluminium alloy. Scripta Mater, 2006, 55: 259–262
Legros M, Kaouache B, Gergaud P, et al. Pipe-diffusion ripening of Si precipitates in Al-0.5%Cu-1%Si thin films. Phil Mag, 2005, 85: 3541–3552
Thomas M E, Keyser T K, Goo E K W. Interfacial CuAl2 precipitate nucleation and growth during the deposition of Al-4%Cu-1.5%Si alloys. J Appl Phys, 1986, 59: 3768–3773
Villars P, Prince A, Okamoto H. Handbook of Ternary Alloy Phase Diagrams (CD Version). Cleveland: ASM International, 1995
Ruan Y, Cao C D, Wei B B. Rapid growth of ternary eutectic under high undercooling conditions. Sci China Ser G-Phys Mech Astron, 2004, 47: 717–728
Mei C X, Ruan Y, Dai F P, et al. Phase constitution and solidification characteristics of undercooled Ag-Cu-Ge ternary eutectic alloy. Acta Phys Sin, 2007, 56: 988–993
Leung K K, Kui H W. Microstructures of undercooled Si. J Appl Phys, 1994, 75: 1216–1218
Author information
Authors and Affiliations
Corresponding author
Additional information
Supported by the National Natural Science Foundation of China (Grant Nos. 50121101, 50395105) and the Doctorate Foundation of Northwestern Polytechnical University (Grant No. CX200419)
About this article
Cite this article
Ruan, Y., Wei, B. Rapid solidification of undercooled Al-Cu-Si eutectic alloys. Chin. Sci. Bull. 54, 53–58 (2009). https://doi.org/10.1007/s11434-008-0540-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11434-008-0540-x