Equation for estimating the Young's modulus, shear modulus and Vickers hardness of aluminosilicate glasses

The Young's modulus, shear modulus and Vickers hardness of alkali oxide-, a lkaline earth oxide- and rare earth oxide-aluminosilicate glasses were meas ured. For the direct calculation of these properties from the glass composi tion, semi-empirical equations expressed in terms of the product of the app arent Madelung constant, the ionic packing ratio and the dissociation energ y of each glass are presented based on Makishima's theory. The apparent Mad elung constant is an empirical parameter which represents the long-range fo rce among the ions in the glass, and the values are calculated using Temple ton-Kapustinsky's equation. The experimental results indicate that the calc ulated values obtained using our proposed equations are in good agreement w ith the measured values for all types of glass examined in this study.