Influence of ultrasonic waves on nucleation and growth of crystalline phases in glasses

Abstract

The problem of the action of ultrasound on the nucleation and growth of crystalline phases in various materials is critically reviewed.

Recent experiments with glasses of the SiO₂-Li₂O-TiO₂ system in the transformation range show that 20 kHz ultrasonic vibrations induce localized crystallization. Quantitative analysis of the phenomenon reveals that the effect observed can be explained in terms of local temperature rise due to the energy dissipated in the region of maximum deformation of the stationary wave.

No effect on nucleation is observed in the temperature range close to the transformation point of the glasses.

On the other hand, preliminary experiments with organic glass-forming liquids (piperine) appear to show that for small undercoolings cavitation in the liquid brings about a multiplication of nuclei which are dispersed by convection currents and this may drastically influence crystallization behaviour of the material.