Effect of Crystallization on the Mechanical Properties of Li ₂ O‐SiO ₂ Glass‐Ceramics

Abstract

Variations in the thermal expansion coefficients, elastic moduli, and fracture strengths of Li 2 O‐SiO 2 glass‐ceramics were determined as a function of nucleation treatment and volume fraction of crystals present. Strength enhancement was attributed to a decrease in the mean free path between crystals as crystallization proceeds. It is postulated that the eventual reduction in strength in some glass‐ceramics is caused by the development of localized cracks at the crystal‐glass interface as a result of the volumetric changes which occur during crystallization.