Effect of Al2O3 content on the mechanical and interdiffusional properties of ion-exchanged Na-aluminosilicate glasses

The effect of the variation in the Al2O3 content on select physical properties of pristine and ion-exchanged glasses in the systems: (75 − x)SiO2mol%-25Na2O-xAl2O3 and (75 − x)SiO2-15Na2O-10CaO-xAl2O3, are reported. The surface compressive stress, surface hardness and K+/Na+ exchange ratio increase, while the depth of the interdiffusion distance decreases, with increasing Al2O3 content. These trends are shown to be consistent with the compositional variation of the glass transition temperature and the molar volume, and their atomistic and thermodynamic bases are discussed.