Chemical Strengthening of Sodium Aluminosilicate Glasses Containing P2O5 and B2O3

Sodium alumino-silicate (SAS) glasses were synthesized with varying P2O5 and B2O3 contents, and their effect on chemical strengthening properties such as surface compressive stress (CS) and depth of layer (DOL) was examined. When P2O5 replaced SiO2, CS decreased, while DOL increased with P2O5 content. In contrast, B2O3 improved CS at the expense of DOL. The simultaneous addition of P2O5 and B2O3 with varying ratios also changed CS and DOL depending on the P2O5 and B2O3 content. The interdiffusion coefficients of K+ ions in SAS glasses were estimated using the Boltzmann-Matano equation and supported the observed effects of P2O5 and B2O3. Structural modifications related to changes in chemical strengthening properties were monitored by Raman spectroscopy and discussed.