Effect of the composition of single-phase alkali-borosilicate glasses on their stability in nitric acid solutions

The chemical stability of single-phase alkali-borosilicate glasses in acid solutions is studied in relation to the glass composition. It is demonstrated, that the chemical stability of glasses equal in the Na2O content reduces, as the molar B2O3/SiO2 ratio in glass rises. The region of B2O3/SiO2 values (1.5-1.8) is established, in which the pattern of interaction between single-phase sodium-borosilicate glasses with HNO3 solutions (unsaturated by the glass components) changes. This interaction results (or doesn't result) in the precipitation of difficult-to-dissolve interaction products on the surface of the specimens. The quantitative and X- ray phase analysis of the phases equilibrium for specified conditions in HNO3 solutions and saturated by the glass components is implemented.