2020 Volume 128 Issue 1 Pages 24-31
This study reports the strengthening effect of partially substituting SiO2 with B2O3 in aluminoborosilicate (ALBS) glasses. Specifically, it investigates how the B2O3 addition affects the ion-exchange behavior of the glass. The base composition of ALBS glass is 13Na2O–5K2O–7MgO–15Al2O3–12B2O3–48SiO2 (mol %). In the prepared samples, the proportion of B2O3 was varied from 0 to 16 mol %. The Na+/K+ inter-diffusion coefficient of each sample was estimated from the K+ ion concentration profile collected along the cross-section of each sample after immersion in molten KNO3 at (Tg × 0.83) K (where Tg is the glass transition temperature) for 8 h. Adding only a small amount of B2O3 drastically changed the K+ ion concentration profile. In contrast, the activation energy of the Na+/K+ inter-diffusion was almost independent of B2O3 content. These results suggest that the B2O3 incorporated in the glasses simply acts as a flux component. These findings are useful for designing compositions that strengthen ion-exchanged glasses.