Characterization of the elasticity and anelasticity of bulk glasses by dynamical subresonant and resonant techniques

The determination of the elastic and anelastic characteristics by means of original non-destructive techniques has been applied to glasses and glass composites in order to link together the macroscopic data with structural aspects. The dynamical Young's modulus determined by a free resonance technique allows a good accuracy measurement. Some examples concerning oxides. Ge(As)Se or metallic glasses are presented: the abrupt drop of the Modulus ill the range of the glass-transition temperature T-g is a general observation, which leads us to all attempt at normalization of the Curves E versus T oil master curves E/E(T-g) versus T/T-g. To study the viscoelastic properties, a low frequency torsional spectrometer is preferentially used to measure the damping due to viscous movements at a microscopic scale. A study of MaSiAlON glasses allows LIS to show that the intrinsic activation energy is much smaller than the one measured by creep or relaxation tests and that the glassy transition is characterized by a smooth change from vitreous solid (highly correlated) to quasi-liquid behavior: this has been confirmed oil a metallic glass. (C) 2003 Elsevier Science B.V. All rights reserved.