Properties of glasses in the system BaO–B2O3–SiO2–xAl2O3 (x=0; 5; 10 mol.%)

Abstract

This article shows the prospect of the system BaO–Al2O3–B2O3–SiO2 as the basis of vitreous and glass ceramic materials, which are widely used in rocket production for high-temperature protection of heat resistant alloys, in the power industry for sealing solid oxide fuel cells, and in the production of heat resistant glass ceramic materials. We examined the conditions of glass formation and properties of glasses with the following content of components (mol.%): BaO 30–70, B2O3 10–50, SiO2 20–60, and Al2O3 0–10. We established experimentally that the physical and chemical properties of glass, depending on its chemical composition, vary within the following limits: coefficient of linear thermal expansion of (71–122)10–7 К–1; glass transition temperature of 500–6500С; dilatometric softening point of 540–6700С; and density of 3.20–4.21 g cm–3. The volume resistivity of the studied glasses is within 1011–1013 Ohmcm at the temperature of 1500С. Generalization of the dependences of glass properties on their chemical composition was carried out with the use of the additive equations, for which the partial contributions of oxides to the values of the corresponding properties were determined by experimental and statistical methods. The established patterns of influence of components and conditions of glass formation on the physical and chemical characteristics of glasses allows implementing the process of designing of a wide range of glass compositions with the complex of specified properties in order to solve the tasks of their practical use.