Sapna Gupta
Articles written in Bulletin of Materials Science
Volume 32 Issue 6 December 2009 pp 611-616 Alloys
Phase diagram of the system Ca–Ti–O at 1200 K
Phase relations in the system Ca–Ti–O have been established by equilibration of several samples at 1200 K for prolonged periods and identification of phases in quenched samples by optical and scanning electron microscopy, XRD and EDS. Samples representing 20 compositions in the ternary system were analyzed. There was negligible solid solubility of Ca in the phases along the binary Ti–O, and of Ti in CaO. Four ternary oxides were identified: CaTiO3, Ca4Ti3O10 and Ca3Ti2O7 containing tetravalent titanium, and CaTi2O4 containing trivalent titanium. Tie-lines link calcium titanite (CaTi2O4) with the three calcium titanates (CaTiO3, Ca4Ti3O10 and Ca3Ti2O7), CaO, oxygen excess TiO1+𝛿 and stoichiometric TiO. Tie-lines connect CaTiO3 with TiO2–𝑥, Magneli phases Ti$_{n}$O$_{2n–1}$ (28 ≥ 𝑛 ≥ 4), Ti3O5, Ti2O3 and TiO1+𝛿. CaO was found to coexist with TiO, and Ti–O solid solutions 𝛼 and 𝛽. The phase diagram is useful for understanding the mechanisms and kinetics of direct calciothermic reduction of TiO2 to metal and electrochemical reduction of TiO2 using graphite anode and molten CaCl2 electrolyte.
Volume 46, 2023
All articles
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
Click here for Editorial Note on CAP Mode
© 2022-2023 Indian Academy of Sciences, Bengaluru.