Abstract
The microstructure of the ternary CaO-SiO2-B2O3 systems in both molten and glassy states were investigated by using in situ high-temperature Raman spectroscopy, quantum chemistry ab initio calculation and molecular dynamics (MD) simulation. Glass samples with varying B2O3 content (0-12 mol%) and basicity ratios (CaO/SiO2 = 1.0 and 1.25) were synthesized via aerodynamic levitation and analyzed to elucidate the structure role of B2O3. The deconvolution of Raman spectra revealed that B2O3 incorporation enhances network polymerization by increasing higher polymerized species while reducing lower polymerized species as a trend consistent in both molten and glassy states. MD results are consistent with these results, showing that B2O3 promotes the conversion of non-bridging oxygen to bridging oxygen, thereby enhancing network connectivity. The weighted relative standard deviation between the experimental and the simulation results lies within the acceptable range, which proves the accuracy and reliability of the conclusion. It provides critical insights into the structure modifications induced by B2O3, offering a theoretical foundation for considering and developing fluoride-free mold fluxes with optimized thermal and mechanical properties for continuous casting processes.