Abstract
The growing demand for increased power output and efficiency of automobiles has led to the recent effort of improving the high-temperature properties of the currently used powertrain alloys. Research into the effects of rare earth additions, such as cerium (Ce), to aluminum (Al) alloys has been gaining momentum due its high-temperature stability associated with its unique Ce-bearing intermetallics. In this study, scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction and neutron diffraction analyses were performed to characterize the microstructure of an Al–6%Ce, Al–16%Ce and an Al–8%Ce–10%Mg alloy. It was observed that the microstructure of the two binary alloys was occupied primarily with fine interconnected Al–Ce eutectic. Additionally, blocky primary Al11Ce3 precipitates were observed in the Al–16%Ce alloy. The large difference in coefficients of thermal expansion between Ce and Al is presumed to be one of the factors leading to the observed extensive microcracking of the primary Al11Ce3 precipitates in the Al–16%Ce alloy and consequently reducing the alloys’ ductility. This reduction in ductility has large implications in terms of usability of the alloy for the targeted powertrain applications. The microstructure of the Al–8%Ce–10%Mg alloy was characterized for the first time and largely consisted of Chinese script or blocky Al11Ce3 precipitates surrounded by a Mg-rich Al matrix. It was found that in addition to solid solution strengthening, the Mg addition may be a factor in altering the fine interconnected Al–Ce eutectic to the coarser Chinese script morphology. This Chinese script morphology is one of the factors restricting dislocations and contributing to the increased strength of the Al–8%Ce–10%Mg alloy at high temperatures, therefore making the alloy suitable for the most demanding engine applications.
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References
Z. Sims, D. Weiss, S. McCall, M. McGuire, R. Ott, T. Geer, O. Rios, P. Turchi, Cerium-based, intermetallic-strengthened aluminum casting alloy: high-volume co-product development. JOM 68(7), 1940–1947 (2016)
D. Weiss, O. Rios, Z. Sims, S. McCall, R. Ott, Casting characteristics of high cerium content aluminum alloys. Light Metals 2017, 205–211 (2017)
Z. Sims, O. Rios, D. Weiss, P. Turchi, A. Perron, J. Lee, T. Li, J. Hammons, M. Hansen, T. Wiley, K. Chen, A. King, S. McCall, High performance aluminum-cerium alloys for high-temperature applications. Materials Horizon. 4(6), 1070–1078 (2017)
D. Weiss, Improved high-temperature aluminum alloys containing cerium. J. Mater. Eng. Perform. 28(4), 1093–1908 (2019)
Weiss D, High performance aluminum casting alloys for engine applications. SAE/JSAE (2016), 2016-32-0019
J. Stroh, T. Davis, A. McDougall, D. Sediako, In situ study of solidification kinetics of Al–Cu and Al–Ce–Mg alloys with application of neutron diffraction. Light Metals 2018, 1059–1065 (2018)
Sediako D, Kasprzak W, Swainson I, Garlea O, Solidification analysis of Al-Si alloys modified with addition of Cu using in-situ neutron diffraction. The minerals, metals & materials society (TMS), aluminum alloys: fabrication, characterization and applications. Supplemental proceedings: Materials fabrication, properties, characterization, and modeling, vol. 2, pp. 279–289
W. Kasprzak, D. Sediako, M. Walker, M. Sahoo, I. Swainson, Solidification analysis of an Al-19 Pct Si alloy using in-situ neutron diffraction. Metall. Mater. Trans. A 42–7, 1854–1862 (2011)
Kasprzak W, Sediako D, Walker M, Sahoo M, Swainson I, Characterization of hypereutectic Al-19% Si alloy solidification process using in-situ neutron diffraction and thermal analysis techniques, in Conference of metallurgists (2010), pp. 121–132
D. Sediako, W. Kasprzak, In situ study of microstructure evolution in solidification of hypereutectic Al–Si alloys with application of thermal analysis and neutron diffraction. Metall. Mater. Trans. A 46–9, 4160–4173 (2015)
ASTM International, B557M Standard test methods for tension testing of metallic materials, ASTM International (2009), pp. 1–27
ASTM International, E3-11 standard guide for preparation of metallographic specimens 1. ASTM International (2011), pp. 1–12
D. Sediako, J. Stroh, A. McDougall, E. Aghaie, Residual stress analysis of A362 aluminum alloy gear case using neutron diffraction. Mater. Sci. Forum Online 941, 1288–1294 (2018)
M. Gao, N. Ünlü, G. Shiflet, M. Mihalkovic, M. Widom, Reassessment of Al–Ce and Al–Nd binary systems supported by critical experiments and first-principles energy calculations. Metall. Mater. Trans. A 36A, 3269–3279 (2005)
Karlsruhe F, Inorganic crystals structures database (Leibniz Institute for Information Infrastructure), https://icsd.fiz-karlsruhe.de/search/index.xhtml;jsessionid=BDB6DC046A694F77D5D5C443909832EF. Accessed Dec 2018
Weiss D. “Composites and Alloys Based on the Al-Ce System, Aluminum Alloys and Composites, 2020
P. Minárik, R. Král, J. Pešička, S. Daniš, M. Janeček, Microstructure characterization of LAE442 magnesium alloy processed by extrusion and ECAP. Mater. Charact. 112, 1–10 (2016)
M. Starink, A. Zahra, β’ and β precipitation in an Al–Mg alloy studied by DSC and TEM. Acta Mater. 46–10, 3381–3397 (1998)
Lu Z, Zhang L, Thermal stability and crystal structure of high temperature compound Al13CeMg6. Intermetallics. 73–76 (2017)
Brabazon D, Raffer A, Advanced characterization techniques for nanostructures, Chapter 3 in emerging nanotechnologies for manufacturing, 2nd Edn (2015), pp. 53–85
Aghaie E, Stroh J, Sediako D, Smith M, In-situ fitness-for-service assessment of aluminum alloys developed for automotive powertrain lightweighting. Light Metals 397–400 (2018)
Acknowledgements
J. Stroh would like to gratefully acknowledge the Rio Tinto Alcan Graduate scholarship which enabled his participation in this study. This work was also funded by Dr. Dimitry Sediako’s NSERC Discovery Grant (RGPIN-2017-004071). The authors would also like to thank the Canadian Nuclear Laboratories (CNL) for the neutron beam time used in the execution of this study and Eck Industries for the motivation and continued support of this research.
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Stroh, J., Sediako, D. & Weiss, D. Development of Cerium-Reinforced Specialty Aluminum Alloy with Application of X-ray and Neutron Diffraction. Inter Metalcast 15, 29–39 (2021). https://doi.org/10.1007/s40962-020-00467-6
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DOI: https://doi.org/10.1007/s40962-020-00467-6