Thermodynamic Description of the Ti–O System using the Ionic Liquid Model for the Liquid Phase

Authors

School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.

Abstract

In this study, the phase diagram and thermodynamic properties of Ti-O system up to 30 mole percent of oxygen was calculated with Calphad method. In this range of oxygen, Ti-O system includes αTi, βTi and liquid phases. αTi and βTi were modeled by “sublattice” model and the model of liquid phase was modeled by “ionic liquid”. Gibbs energy parameters of each phase was optimized by Thermo-Calc software and their phase and thermodynamic diagrams were drawn using this software. The obtained results were compared with experimental and other calculated results. A good accordance was observed between calculated and experimental results. In calculation of phase diagram, with increasing temperature and mole fraction of oxygen, the use of “ionic liquid” model instead of “sublattice” model in thermodynamic description of liquid phase showed better accordance with experimental data.

Keywords


1. Saunders, N., and Chandrasekaran, L., “Phase Diagram Modeling for Titanium Alloys with Light Element Impurities”, Journal of Phase Equilibria, Vol. 13, No. 6, pp. 612-619, 1992.
2. Pajunen, M., and Kivilahti, J., “Thermodynamic Analysis of the Titanium-Oxygen System”, Zeitschrift fuer Metallkunde, Vol. 83, No. 1, pp. 17-20, 1992.
3. Fischer, F., “Thermodynamic Calculation of the O-Ti System”, Journal of Phase Equilibria, Vol. 18, No. 4, pp. 338-343, 1997.
4. Lee, B. J., and Saunders, N., “Thermodynamic Evaluation of the Ti-Al-O Ternary System”, Zeitschrift fuer Metallkunde, Vol. 88, No. 2, pp. 152-161, 1997.
5. Eriksson, G., Pelton, A. D., Woermann, E., and Ender, A., “Measurement and Thermodynamic Evaluation of Phase Equilibria in the Fe‐Ti‐O System”, Berichte der Bunsengesellschaft für physikalische Chemie, Vol. 100, No. 11, pp. 1839-1849, 1996.
6. Waldner, P., and Eriksson, G., “Thermodynamic Modelling of the System Titanium-Oxygen”, Calphad, Vol. 23, No. 2, pp. 189-218, 1999.
7. Cancarevic, M., Zinkevich, M., and Aldinger, F., “Thermodynamic Description of the Ti-O System using the Associate Model for the Liquid Phase”, Calphad, Vol. 31, No. 3, pp. 330-342, 2007.
8. Hampl, M., and Schmid-Fetzer, R., “Thermodynamic Description of the Ti-O System”, International Journal of Materials Research, Vol. 106, No. 5, pp. 439-453, 2015.
9. Lukas, H. L., Fries, S. G., and Sundman, B., Computational Thermodynamics: the Calphad Method, Vol. 131. Cambridge University Press Cambridge, 2007.
10. Bumps, E. S., Kessler, H. D., and Hansen, M., “The Titanium-Oxygen System”, Transactions of American Society for Metals, Vol. 45, pp. 1008-1028, 1953.
11. Schofield, T. H., and Bacon, A. E., “The Constitution of the Titanium-Oxygen Alloys in the Range 0-35 Weight Percent Oxygen”, Journal of the Institute of Metals, Vol. 84, pp. 47-53, 1955.
12. Ariya, S. M., Morozova, M. P., and Volf, E., “Khimiya Soedinenii Peremennogo Sostava. 6. Sistema Titan Kislorod”, Zhurnal Neorganicheskoi Khimii, Vol. 2, No. 1, pp. 13-22, 1957.
13. Mah, A. D., Kelley, K. K., Gellert, N. L., King, E. G., and O’Brien, C. J., “Thermodynamic Properties of Titanium-Oxygen Solutions and Compounds”, Bureau of Mines, RPRT, 1955.
14. Hepworth, M. T., and Schuhmann, R., “Thermodynamic Properties of Titanium-Oxygen-Hydrogen Alloys”, Transactions of the Metallurgical Society of AIME, Vol. 224, No. 5, p. 928, 1962.
15. Boureau, G., and Gerdanian, P., “Thermodynamic Study of Interstitial Solid Solutions of Oxygen in Titanium at 1050 C”, Acta Metallurgica., Vol. 24, No. 8, pp. 717-723, 1976.
16. Okabe, T. H., Suzuki, R. O., Oishi, T., and Ono, K., “Thermodynamic Properties of Dilute Titanium-Oxygen Solid Solution in Beta Phase”, Materials Transactions , The Japan Institute of Metals, Vol. 32, No. 5, pp. 485-488, 1991.

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