Effect of Bi₂O₃ Addition on Structure and Properties of SiO₂-Al₂O₃-MgO Glass

SiO₂-Al₂O₃-MgO glass added with Bi₂O₃ of different mass fractions (0-3.0wt%) was prepared by conventional melt quenching technique, and the effect of Bi₂O₃ addition amount on the thermal stability, structural stability and physical and mechanical properties was investigated. The results show that Bi₂O₃ addition effectively reduced the softening point of glass. The difference between glass crystallization temperature and glass transition temperature increased first and then decreased, and the optical band gap decreased first and then increased with increasing Bi₂O₃ addition amount, indicating that the thermal stability and structural stability decreased first and then increased; the bulk density, bending strength, compressive strength and compressive modulus of glass also increased first and then decreased. When the content of Bi₂O₃ was 1.5wt%, the thermal stability, structural stability and physical and mechanical properties of glass were the best, with the difference between glass crystallization temperature and glass transition temperature of 244 K, optical band gap of 3.50 eV, bulk density of 2.67 g·cm^-3, bending strength of 82.72 MPa, compressive strength of 236.24 MPa, and compressive modulus of 110.06 GPa.