Dual functional roles of lithium oxide in mixed alkaline earth aluminosilicate fiber glasses

Research of advanced glass fiber in the MgO-CaO-Al2O3-SiO2 (MCAS) system has drawn worldwide attention for more than a decade because of its unique mechanical properties, high modulus, and high strength, for ultralong wind turbine blades. However, challenges remain in processing technology because of its inherent high liquidus temperature. For the first time, we achieved a significant reduction in the liquidus temperature of the MCAS glass using the Li2O modification to the MCAS glass along with the reduction in the melt viscosity. Though being a glass network modifier like other alkali oxides, surprisingly, Li2O in glass further increases MCAS glass fiber sonic modulus. The dual functional roles of Li2O discovered from this study resemble previous findings on rare earth oxides in the MCAS glasses. The current findings are supported by experimental measurements, Raman spectroscopic study, and molecular dynamics simulations.