Investigation of microheterogeneities in Ga–Pb melts by acoustic methods

The pulse phase method of measuring the ultrasound velocity V, was used for investigation of the microheterogeneity of hypermonotectic Ga-Pb melts. The method allows measuring V s at various distances from the bottom of the crucible. An anomalous variation of the ultrasound velocity along the vertical axis of the crucible both in two-phase and the one-phase regions of the phase diagram was observed. The effect disappears irreversibly after a sufficient overheating the melt above the phase separation line. The phenomenon is linked with a metastable microheterogeneity of investigated melts. An experimental method to detect microdroplets inside the liquid solution is proposed and their volume fraction and mean size are calculated.