Abstract
The addition of traces of Sr to AlSi foundry alloys induces a flake-to-fibrous transition of the eutectic phase which enhances tensile, impact and thermal shock properties. Since this modification is not always completely homogenous, the underlying mechanisms have to be reviewed. In this work the three dimensional Sr distribution in eutectic Si was analyzed by Laser Pulsed Atom Probe Tomography. Well modified fibers revealed nanometric segregations rich in Al and Sr. These features presented cluster-, planar- and rod-like morphologies which can be related to mechanisms involved in Si growth restriction. This finding reinforces the fact that Sr has a direct influence on the growth mechanism of eutectic Si.
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References
John E. Gruzleski, and Bernard Closset, Treatment of Liquid Aluminum-Silicon Alloys (Amer Foundrymens Society, 1990).
L. Clapham, and R. Smith, “Segregation behaviour of strontium in modified and unmodified Al-Si alloys,” Journal of Crystal Growth, 92 (1988), 263–270.
S. Lu, and A. Hellawell, “The mechanism of silicon modification in aluminum-silicon alloys: impurity induced twinning,” Metallurgical and Materials Transactions A, 18 (1987), 1721–1733.
K. Nogita et al., “Determination of strontium segregation in modified hypoeutectic Al-Si alloy by micro X-ray fluorescence analysis,” Scripta Materialia, 55 (2006), 787–790.
C.J. Simensen et al., “NanoSIMS Analysis of Trace Element Segregation during the Al-Si Eutectic Reaction,” Metallurgical and Materials Transactions A, 38 (2007), 1448–1451.
F. Lasagni et al., “Three Dimensional Characterization of Unmodified and Sr-Modified Al-Si Eutectics by FIB and FIB EDX Tomography,” Advanced Engineering Materials, 8 (2006), 719–723.
K. Kobayashi, and L. Hogan, “The crystal growth of silicon in Al-Si alloys,” Journal of Materials Science, 20 (1985), 1961–1975.
M.G. Day, and A. Hellawell, “The Micro structure and Crystallography of Aluminium-Silicon Eutectic Alloys,” Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 305 (1968), 473–491.
M. Shamsuzzoha, and L.M. Hogan, “The twinned growth of silicon in chill-modified Al-Si eutectic,” Journal of Crystal Growth, 82 (1987), 598–610.
M. Shamsuzzoha, and L.M. Hogan, “The crystal morphology of fibrous silicon in strontium-modified Al-Si eutectic,” Philosophical Magazine A, 54 (1986), 459–477.
J. Chang, and H. Ko, “Twin probability of eutectic Si in rare earth modified Al-7wt% Si alloy,” Journal of Materials Science Letters, 19(2000), 197–199.
K. Nogita, J. Drennan, and A. Dahle, “Evaluation of silicon twinning in hypo-eutectic Al-Si alloys,” Materials Transactions, 44 (2003), 625–628.
Y.H. Cho et al., “Effect of Strontium and Phosphorus on Eutectic Al-Si Nucleation and Formation of β-A15FeSi in Hypoeutectic Al-Si Foundry Alloys,” Metallurgical and Materials Transactions A, 39 (2008), 2435–2448.
A.K. Dahle et al., “Eutectic nucleation and growth in hypoeutectic Al-Si alloys at different strontium levels,” Metallurgical and Materials Transactions A, 32 (2001), 949–960.
S.D. McDonald et al., “Eutectic grains in unmodified and strontium-modified hypoeutectic aluminum-silicon alloys,” Metallurgical and Materials Transactions A, 35 (2004), 1829–1837.
M. Timpel et al., “The role of strontium in modifying aluminium-silicon alloys,” Acta Materialia, 60 (2012), 3920–3928.
K. Thompson et al., “In situ site-specific specimen preparation for atom probe tomography.,” Ultramicroscopy, 107 (2007), 131–9.
O. Hellman et al., “Analysis of Three-dimensional Atom-probe Data by the Proximity Histogram.,” Microscopy and Microanalysis: the Official Journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada, 6 (2000), 437–444.
O.C. Hellman, J.B. du Rivage, and D.N. Seidman, “Efficient sampling for three-dimensional atom probe microscopy data.,” Ultramicroscopy, 95 (2003), 199–205.
M.D. Hanna, S.-Z. Lu, and A. Hellawell, “Modification in the aluminum silicon system,” Metallurgical Transactions A, 15 (1984), 459–469.
B. Gault et al., Atom Probe Microscopy (Springer New York, New York, NY, 2012)185:188.
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Barrirero, J., Engstler, M., Mücklich, F. (2016). Atom Probe Analysis of Sr Distribution in AlSi Foundry Alloys. In: Sadler, B.A. (eds) Light Metals 2013. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-319-65136-1_50
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DOI: https://doi.org/10.1007/978-3-319-65136-1_50
Publisher Name: Springer, Cham
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