Retarded Elasticity in SiO₂-Na₂O and B₂O₃-Na₂O Glasses

Abstract

The retarded elasticity was investigated for SiO₂-Na₂O and B₂O₃-Na₂O glasses by using a compressive method in the transition range. The compliance (J_∞) determined at the final stage of each measurement displayed a maximum as a function of viscosity of glass in both systems and was simulated by the same equation applied for As-Se glasses reported in a previous paper. J_∞=(1-k₂η_G/η)(f₁[k₁/η]+f₂[nk₁/η]) (3) where k₁, k₂, f₁, f₂ and n are parameters and η_G is the viscosity related to the retarded elasticity. The terms [k₁/η] and [nk₁/η] are assumed to be equal to unity for all values exceeding one. Therefore, the experimental Equation (3) is valid for the oxide glasses in the systems SiO₂-Na₂O and B₂O₃-Na₂O.