Structure, thermal stability and spinnability of the CaO-MgO-Al2O3-SiO2 glasses with SiO2 replaced by Al2O3

In this paper, the structure, thermal stability, spinnability and fiber tensile strength of the CaO-MgO-Al2O3-SiO2 glasses with SiO2 replaced by Al2O3 were studied by FT-IR, DSC, dilatometry, rotating viscometer and tensile strength. Results show that with the molar ratio of Al2O3 to SiO2 (A/S) increasing, the polymerization degree of glass network structure increases, which results in a significant rise of Tg and thermal stability parameters (Delta T, S). The characteristic temperatures and fragility of glassy melts derived from viscosity tests and the MYEGA model increase with the ascent of A/S. The fiber spinnability parameters (Tl-Tlog3, Kfib) show a different trend as the A/S increases, but both indicating the feasibility of continuous fiberglass production, confirmed by experi-ments. The fiber tensile strength increases as the A/S increases or the fiber diameter decreases. Furthermore, with the same fiber diameter, the glass fiber produced at higher spinning temperature exhibits higher tensile strength