| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
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| Symposium
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Materials Processing Fundamentals: Thermodynamics and Rate Phenomena
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| Presentation Title |
Novel approach to measure the thermodynamic property of tri-calcium phosphate using the phase relation in the CaO-SiO2-P2O5 ternary system |
| Author(s) |
Keijiro Saito, Kazuki Morita, Masakatsu Hasegawa |
| On-Site Speaker (Planned) |
Keijiro Saito |
| Abstract Scope |
Although several researchers reported the thermodynamic property of tri-calcium phosphate, their results exhibited large discrepancies, which could be a significant problem in material production. All previous studies were based on the CaO-P2O5 binary system, and their results for Ca3P2O8 include the inaccuracies originating from used thermodynamic data, e.g., Ca4P2O9 or phosphorus in reference metals. In contrast, this study focused on the CaO-SiO2-P2O5 ternary system as a novel approach. Oxide mixtures of Ca3P2O8+CaSiO3+SiO2 and Mg3P2O8+MgO were equilibrated with Cu-P alloys under an Ar+H2+H2O atmosphere. By combining thermodynamic data for CaSiO3 and Mg3P2O8, which were well assessed in the literature, the standard Gibbs energy of Reaction (1) was determined.
P2(gas) + (5/2)O2(gas) + 3CaO(solid) = Ca3P2O8(solid) (1)
Intrinsic systematic errors in the thermodynamic data for the Cu-P alloy would be canceled out in deriving Reaction (1) from the experiment with the two types of oxide mixtures. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, |