Abstract
Small additions of beryllium (Be) to aluminum magnesium (AlMg) alloys have proven to decrease their oxidation rate during industrial liquid metal handling. As Be can cause respiratory health issues, it is desirable to evaluate alternative methods to inhibit the oxidation rate. Earlier work has revealed that small amounts of carbon dioxide (CO2) to the surrounding atmosphere has a positive effect. In the present study the oxidation behavior of an aluminum magnesium silicon (AlMgSi) alloy has been investigated using a Differential Scanning Calorimetric (DSC) unit equipped with a Thermogravimetric Analyzer (TGA). Changes in both the heat flux and the mass have been monitored during exposer to 20% argon (Ar) and 80% synthetic air, 99.999% pure Ar, and a gaseous mixture of 20% Ar, 76% synthetic air and 4% CO2 at 750 °C for 7 h. The results revealed a one-step mass gain when heated in synthetic air, giving a total mass gain of 12.33% and an oxide layer thickness of >15 µm. Pure Ar had a positive effect on the oxidation rate lowering the mass gain to 2.80% and a thickness of ~10 µm. A mass gain of only 0.46% and a continuous dense oxide layer of 200–400 nm, with an additional granular discontinuous oxide layer of ~2 µm underneath, was obtained during heating in 4% CO2. This confirms that even in the case of the AlMgSi alloy, small amounts of CO2 have a significant inhibiting effect on the oxidation rate.
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References
K. Surla, F. Valdivieso, M. Pijolat, M. Soustelle, and M. Prin, “Kinetic study of the oxidation by oxygen of liquid Al–Mg 5% alloys,” Solid State Ionics, vol. 143, no. 3, pp. 355–365, Jul. 2001.
N. Smith, B. Gleeson, W. A. Saidi, A. Kvithyld, and G. Tranell, “Mechanism behind the Inhibiting Effect of CO2 on the Oxidation of Al–Mg Alloys,” Ind. Eng. Chem. Res., vol. 58, no. 3, pp. 1434–1442, Jan. 2019.
D. L. Belitskus, “Oxidation of molten Al-Mg alloy in air, air-SO2, and air-H2S atmospheres,” Oxid Met, vol. 3, no. 4, pp. 313–317, Jul. 1971.
G. Wightman and D. J. Fray, “The dynamic oxidation of aluminum and its alloys,” MTB, vol. 14, no. 4, pp. 625–631, Dec. 1983.
N. Ünlü and M. G. Drouet, “Comparison of salt-free aluminum dross treatment processes,” Resources, Conservation and Recycling, vol. 36, no. 1, pp. 61–72, Jul. 2002.
N. Smith, “Methods of oxidation inhibition for Al–Mg alloys,” Ph.D. Thesis, NTNU, Norwegian University of Science and Technology, Trondheim, 2019.
C. N. Cochran, D. L. Belitskus, and D. L. Kinosz, “Oxidation of aluminum-magnesium melts in air, oxygen, flue gas, and carbon dioxide,” MTB, vol. 8, no. 1, pp. 323–332, Mar. 1977.
H. Venugopalan and T. DebRoy, “Kinetics of directed oxidation of Al-Mg alloys into A12O3 preforms,” Materials Science and Engineering: A, vol. 232, no. 1, pp. 39–46, Jul. 1997.
C. Blawert, N. Hort, and K. U. Kainer, “AUTOMOTIVE APPLICATIONS OF MAGNESIUM AND ITS ALLOYS,” TRANS. INDIAN INST. MET., vol. 57, no. 4, p. 12, 2004.
C. N. Cochran and W. C. Sleppy, “Oxidation of high-purity aluminum and 5052 aluminum-magnesium alloy at elevated temperatures,” J. Electrochem. Soc., vol. 108, no. 4, pp. 322–327, Apr. 1961.
I. Haginoya and T. Fukusako, “Oxidation of molten Al–Mg alloys,” Trans. JIM, vol. 24, no. 9, pp. 613–619, 1983.
J. Steglich, C. Matthies, M. Rosefort, and B. Friedrich, “Behavior of Mg–Si-rich phases in aluminum can sheets and their impact on metal oxidation during industrial thermal pre-treatment,” in Light Metals 2018, 2018, pp. 1123–1130.
N. Smith, A. Kvithyld, and G. Tranell, “The mechanism behind the oxidation protection of high Mg Al alloys with beryllium,” Metall and Materi Trans B, vol. 49, no. 5, pp. 2846–2857, Oct. 2018.
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Acknowledgements
The authors would like to thank the Department of Materials Science and Engineering at the Norwegian University of Science and Technology (NTNU), Trondheim, Norway, the Centre for Research-Based Innovation (SFI Metal Production), and the Research Council of Norway (NFR Project number 237738) for funding the project.
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Solem, C.K.W., Ekstrøm, K.E., Tranell, G., Aune, R.E. (2020). Evaluation of the Effect of CO2 Cover Gas on the Rate of Oxidation of an AlMgSi Alloy. In: Tomsett, A. (eds) Light Metals 2020. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-030-36408-3_154
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DOI: https://doi.org/10.1007/978-3-030-36408-3_154
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