Elastic properties and Vickers hardness of optically transparent glass–ceramics with fresnoite Ba 2TiSi 2O 8 nanocrystals

Abstract

Optically transparent glass–ceramics (40BaO–20TiO 2–40SiO 2 (mol%)) consisting of nonlinear optical fresnoite Ba 2TiSi 2O 8 (BTS) nanocrystals (diameter: 100–200 nm) are fabricated, and their elastic properties and deformation behavior are examined as a function of the volume fraction ( f) of BTS nanocrystals using cube resonance and Vickers indentation techniques. The elastic properties such as Young's modulus ( E) increases linearly with increasing the volume fraction of nanocrystals, e.g., E = 84 GPa for f = 0% (glass) to E = 107 GPa for f = 54.5%. The Vickers hardness ( H v) and indentation fracture toughness ( K c) increase from 5.0 to 6.0 GPa for H v and 0.48 to 1.05 MPa m −1/2 for K c with increasing the volume fraction (from f = 0% to f = 54.5%), but they do not change linearly against the volume fraction of nanocrystals. It is suggested that BTS nanocrystals themselves induce a high resistance against deformation during Vickers indenter loadings.