Formation of metal microspheres by ultrasonic cavitation

A new physical method is described for the preparation of metal microspheres by ultrasonic cavitation of low-melting point metals (<380 degrees C) immersed in hot silicone oil. The ultrasonic radiation causes dispersion of the molten metals into spheres, which solidify rapidly on cooling. This method is illustrated for the synthesis of Pb and Au-Si eutectic alloy.