Unraveling the relationship between the multilayer network structure and mechanical properties of alkali-free aluminosilicate glass

Alkali-free aluminosilicate glass has several advantages, including a low thermal expansion coefficient and density, high elastic modulus, and excellent chemical and thermal stability, making it an ideal substrate material for TFT-LCD and OLED applications. Understanding the relationship between the composition-microstructure-properties of this glass is crucial for designing materials with optimal properties and suitable process parameters. In this work, we investigated how the composition affects the microstructure and properties of alkali-free aluminosilicate substrate glass. We elucidated the relationship between composition-microstructure-properties through experiments and molecular dynamics simulations. As B₂O₃ replaced Al₂O₃ in the glass, the content of [AlO₄] in the network structure decreased, while the amounts of [BO₃] and [BO₄] increased. The triangular structure of [BO₃] expanded the network, reduced its connectivity, and loosened the overall structure. Consequently, the glass melt's viscosity, viscous activation energy, and melting temperature decreased. This study provided essential data and a theoretical foundation for industrial production based on the composition-microstructure-properties relationship.