|About this Abstract
||Materials Science & Technology 2017
||Phase Stability, Diffusion Kinetics, and Their Applications (PSDK-XII)
||Thermodynamic Optimization of the Na2O-B2O3-SiO2 System
||Evgenii Nekhoroshev, Sergei Decterov
|On-Site Speaker (Planned)
Expansion of the oxide thermodynamic database to systems containing both B2O3 and alkali oxides is important for the glass industry, mold fluxes and other applications. The key system for this database development is Na2O-B2O3-SiO2 and its binary subsystems. These systems are particularly challenging due to the presence of two network formers, B2O3 and SiO2, which exhibit very strong interactions with alkali oxides. Furthermore, spectroscopic and NMR studies of B2O3 and Na2O-B2O3 melts, as well as several anomalies in physical properties, indicate the formation of clusters which can contain boron cations in both trigonal and tetrahedral coordination. Finally, metastable miscibility gaps are present in the Na2O-SiO2, Na2O-B2O3 and Na2O-B2O3-SiO2 systems and are fairly well studied. However, borosilicate systems containing alkali oxides have hitherto eluded adequate thermodynamic modeling. In the present study, the Na2O-B2O3-SiO2 system is optimized using a model for the liquid phase developed within the Modified Quasichemical Formalism.
||Definite: At-meeting proceedings