The Effect of the Sound Pressure and Frequency on the Crystallization of 65CaO-25Ga2O3-10GeO2

Abstract

As a part of a containerless melting experiments in space, a 65CaO-25Ga2O3-10GeO2 (mol %) composition will be melted in an acoustic levitation furnace (ALF). The effect of the acoustic field on the crystallization tendency of this composition has been investigated as a function of sound pressure level (SPL) and frequency. The critical cooling rate for glass formation, as measured in ALF without the acoustic field, was the same as that measured previously. Sound pressure levels up to 155 dB, frequency of 11 to 11.1 kHz at 5Hz steps has no effect on the temperature of crystallization for a melt cooled at 200 deg　C/min nor on the tendency to form a glass for melts cooled at 1000 deg　C/min. Sound fields with a frequency between 11 and 15 kHz had no effect on the crystallization for melts cooled at 500 deg　C/min. Similarly the crystallization was un affected when that was swept at either 5 or 20 Hz.