Abstract
The present work was undertaken to study the effect of 1.0 and 5.0 wt% additions of rare earths, RE (Ce/La), on the solidification behavior and microstructural characteristics of two as-cast alloys under low solidification rate conditions (0.7 °C/s). The alloys studied contain Al–1.2Si–2.4Cu–0.4Mg–0.4Fe–0.6Mn–0.15Ti wt% and Al–8.0Si–2.4Cu–0.4Mg–0.4Fe–0.6Mn–0.15Ti wt%. These two alloys are coded B0 and D0, respectively. Thermal analysis and differential scanning calorimetry (DSC) were used to examine the solidification behavior of the alloys. The thermal analysis results revealed that the main phases observed in the alloys are α-Al, α-Fe, Al–Si, Al2Cu and Q–Al5Cu2Mg8Si6 phases. The results also showed a drop in the nucleation temperature of α-Al and eutectic temperature (Al–Si) caused by the addition of RE (Ce/La); the drop was more readily observed with the 5.0 wt% RE (Ce/La) addition. Differential scanning calorimetry revealed that the addition of La or Ce leads to the appearance of exothermic peaks between the precipitation of the primary α-Al phase and the (Al–Al2Cu) eutectic reaction in the solidification and heating curves. Moreover, the peak corresponding to the formation of the Al2Cu phase is clearly noticeable in the base alloys, becomes smaller with 1.0 wt% RE (Ce/La) and then disappears with 5.0 wt% RE (Ce/La) additions. This can be attributed to the interactions between the RE (Ce/La) and Cu in the alloys considered. Since the thickness of precipitated RE intermetallic platelets is about 1 µm, it is difficult to obtain their stoichiometric compositions using WDS analysis.
Similar content being viewed by others
References
R. Sharan, N.P. Saksena, Rare earth additions as modifiers, of aluminum silicon alloys. AFS Int. Cast Metals J. 3(1), 29–33 (1978)
B.J. Ye, D.Y. Lu, C.S. Kang, An assessment of the role of rare earth in the eutectic modification of cast aluminum-silicon alloys. AFS Trans. 93, 533–544 (1985)
K. Nogita, S.D. McDonald, A.K. Dahle, Eutectic modification of Al–Si alloys with rare earth metals. Mater. Trans. 45, 323–326 (2004)
M.F. Ibrahim, M.H. Abdelaziz, A.M. Samuel, H.W. Doty, F.H. Samuel, Effect of rare earth metals on the mechanical properties and fractography of Al–Si-based alloys. Int. J. Metalcast. (2019). https://doi.org/10.1007/s40962-019-00336-x
H. Ye, An overview of the development of Al–Si alloy, based material for engine applications. J. Mater. Eng. A. 12, 288–297 (2003)
J. Gröbner, D. Mirkovic, R. Schmid-Fetzer, Thermodynamic aspects of the constitution, grain refining, and solidification enthalpies of Al–Ce–Si alloys. Metall. Mater. Trans. A 35A, 3351–3362 (2004)
J. Gröbner, D. Kevorkov, R. Schmid-Fetzer, Thermodynamic modeling of Al–Ce–Mg phase equilibria coupled with key experiments. Intermetallics 10, 415–422 (2002)
B.A. Mueller, J.H. Perepezko, The undercooling of aluminum. Metall. Trans. A 18, 1143–1150 (1991)
Z.C. Sims, O.R. Rios, D. Weiss, P.E.A. Turchi, A. Perron, J.R.I. Lee, T.T. Li, J.A. Hammons, M. Bagge-Hansen, T.M. Willey, K. An, Y. Chen, A.H. King, S.K. McCall, High performance aluminum–cerium alloys for high-temperature applications. Mater. Horizons https://doi.org/10.1039/c7mh00391a
Z.C. Sims, D. Weiss, S.K. McCall, M.A. McGuire, R.T. Ott, T. Geer, O. Rios, P.A.E. Turchi, Cerium-based, intermetallic-strengthened aluminum casting alloy: high-volume co-product development. J. Min. Met. Mat. S. 68(7), 1940–1947 (2016)
J. Stroh, T. Davis, A. McDougal, D. Sediako, In situ study of solidification kinetics of Al–Cu and Al–Ce–Mg alloys with application of neutron diffraction. TMS 2018 https://doi.org/10.1007/978-3-319-72284-9
M.G. Mahmoud, A.M. Samuel, H.W. Doty, S. Valtierra, F.H. Samuel, Effect of solidification rate and rare earth metal addition on the microstructural characteristics and porosity formation in A356 alloy. Adv. Mater. Sci. Eng. 2017, 5086418 (2017). https://doi.org/10.1155/2017/5086418
E.M. Elgallad, H.W. Doty, S.A. Alkahtani, F.H. Samuel, Effects of La and Ce addition on the modification of Al–Si based alloys. Adv. Mater. Sci. Eng. 2016, 5027243 (2016). https://doi.org/10.1155/2016/5027243
A.M. Samuel, E.M. Elgallad, H.W. Doty, S. Valtierra, F.H. Samuel, Rare earth metal-based intermetallics formation in Al–Cu–Mg and Al–Si–Cu–Mg alloys: a metallographic study. Adv. Mater. Sci. Eng. 2018, 7607465 (2018). https://doi.org/10.1155/2018/7607465
J. Hernandez-Sandoval, A.M. Samuel, S. Valtierra, F.H. Samuel, Thermal analysis for detection of Zr-rich phases in Al–Si–Cu–Mg 354-type alloys. Int. J. Metalcast. 11, 428–439 (2017)
L. Backerud, G. Chai, J. Tamminen, Solidification characteristics of aluminum alloys, Vol. 2. Foundry alloys, American Foundry men’s Society Inc (1990)
S.A. Alkahtani, E.M. Elgallad, M.M. Tash, A.M. Samuel, F.H. Samuel, Effect of rare earth metals on the microstructure of Al–Si based alloys. Materials 9, 45 (2016). https://doi.org/10.3390/ma9010045
M.G. Mahmoud, A.M. Samuel, H.W. Doty, S. Valtierra and F.H. Samuel, Effect of rare earth metals, Sr, and Ti addition on the microstructural characterization of A413.1 alloy. Adv. Mater. Sci. Eng. 2017, 4712946 (2017). https://doi.org/10.1155/2017/4712946
S. Farahany, A. Ourdjini, M. Idrsi, S. Shabestari, Evaluation of the effect of Bi, Sb, Sr and cooling condition on eutectic phases in an Al–Si–Cu alloy (ADC12) by in situ thermal analysis. Thermochim. Acta 559, 59–68 (2013)
Y.C. Tsai, S.L. Lee, C.K. Lin, Effect of trace Ce addition on the microstructures and mechanical properties of A356 (AL–7SI–0.35Mg) aluminum alloys. J. Chin. Inst. Eng. 34, 609–616 (2011)
M. Voncina, P. Mrvar, M. Petric, J. Medved, Microstructure and grain refining performance of Ce on A380 alloy. J. Min. Metall.Sect. B. 48, 265–272 (2012)
R. Ahmad, M.B.A. Asmael, N.R. Shahizan, S. Gandouz, Reduction in secondary dendrite arm spacing in cast eutectic Al-Si piston alloys by cerium addition. Int. J. Minerals Metall. Mater. 24, 91–101 (2017)
F. Mao, G.Y. Yan, J.Q. Li, T.M. Wang, Z.Q. Cao, The interaction between Eu and P in high purity Al-7Si alloys. Mater. Charact. 120, 129–142 (2016)
A.M.A. Mohamed, A.M. Samuel, F.H. Samuel and A.M.A. Al-Ahmari, Effects of rare earths on the as-cast microstructure of an Al–Si–Mg alloy, in Transactions of the American Foundry Society: 115th Metalcasting Congress, April 5-8 (Schaumburg, IL), 119 (2011), pp. 83–91
A.M. Samuel, H.W. Doty, S. Valtierra, F.H. Samuel, Beta Al5FeSi phase platelets-porosity formation relationship in A319.2 type alloys. Int. J. Metalcast. 12(1), 55–70 (2018)
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Mahmoud, M.G., Samuel, A.M., Doty, H.W. et al. Effect of the Addition of La and Ce on the Solidification Behavior of Al–Cu and Al–Si–Cu Cast Alloys. Inter Metalcast 14, 191–206 (2020). https://doi.org/10.1007/s40962-019-00351-y
Published:
Issue Date:
DOI: https://doi.org/10.1007/s40962-019-00351-y