Influence of Y2O3 substitution for B2O3 on the structure and properties of alkali-free B2O3-Al2O3-SiO2 glasses containing alkaline-earth metal oxides

In this work, alkali-free B2O3-Al2O3-SiO2 glasses containing alkaline-earth metal oxides were prepared by conventional melt-quenching method. Influence of Y2O3 substitution for B2O3 on the structure and properties of the glasses was systematically discussed. The structural variations of the glasses doped with different Y2O3 content were studied by FT-IR spectroscopy. Simultaneously, the relationship between the structure and related properties of the glasses including density, thermal expansion coefficient, strain point, compressive strength, bending strength, Vickers hardness, chemical durability and light transmittance was also investigated. The study on FT-IR spectra shows that Y2O3 acts as a network modifier and destroys the glass network structure. In terms of the properties of the glasses, with the increase of Y2O3 content at the expense of B2O3, the density and thermal expansion coefficient increase, while the chemical durability and transmittance decline. In addition, the compressive strength and bending strength decrease first and then increase, but the replacement of Y2O3 has less effect on the strain point and Vickers hardness. Each of the designed glasses possesses good transmittance (above 80%), very high strain point (near 732 degrees C) and excellent chemical durability.