Physicochemical Properties of Glasses in SrO · B2O3–SrO · SiO2 Join

Abstract

The physicochemical properties of glasses in the 50SrO · 50B₂O₃–50SrO · 50SiO₂ join (mol %), such as density, microhardness, thermal expansion, and glass-transition temperature, are studied. Comparison with the characteristics of strontium-borosilicate glasses in other join with the constant strontium oxide content shows that the molar volume increases with an increase in the concentration of B₂O₃ and does not depend on the SrO content in the range of 50 to 35 mol %. It is determined that the glass-transition temperature decreases with the replacement of SiO₂ by B₂O₃. The concentration dependences of the microhardness, thermal expansion coefficient above the glass transition region (α_l), and the change of the thermal expansion coefficient in the glass transition region (Δα) have a maximum in the composition range rich in boron oxide.