Abstract
Phase relations in the CaO–TiO2 system are of considerable interest in geology, metallurgy, and ceramics. Despite a number of studies of phase equilibria in the CaO–TiO2 system, there are still some open questions regarding the stability of intermediate compounds. In this work, a series of specimens with different CaO:TiO2 ratios were prepared by solid-state reaction. The heat capacities of Ca3Ti2O7 and Ca4Ti3O10 from 300 to 1073 K were measured by differential scanning calorimetry and their formation enthalpies from the component oxides at 298 K were measured by high temperature oxide melt solution calorimetry. Using phase diagram information and thermodynamic data from the literature and the present measurements, thermodynamic optimization of the CaO–TiO2 system was carried out by the CALPHAD technique. The phase diagram and the thermodynamic properties of the CaO–TiO2 system were calculated using the obtained thermodynamic database, which clarify the stable and metastable phase equilibria of the system. The thermodynamic stability of the various compounds was discussed.
Original language | English (US) |
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Pages (from-to) | 1361-1370 |
Number of pages | 10 |
Journal | Journal of the American Ceramic Society |
Volume | 101 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2018 |
Externally published | Yes |
Keywords
- CaO–TiO system
- enthalpy of formation
- heat capacity
- phase diagram
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry