The study of the liquid metal drops fragmentation

Abstract

The main models of the fragmentation of liquid metal droplets in a steam explosion based on thermal stress, shock-acoustic effects and explosive boiling water inside the melt were analyzed. Experimental installations are described and research results are presented. The experiments were carried out with samples of various metals (tin, nickel, zinc, stainless steel), which were heated in levitation mode using an inductor. The maximum temperature for heating a sample of ball-bearing steel did not exceeded 1600 °C. Then, in the molten state, the samples (droplets) fell into a cell filled with distilled water at room temperature. In the experiments, the temperature of the melting sample was monitored and the crushing process was recorded. An experimental material indicating the diversity of the forms of the fragments being formed was obtained. The latter circumstance confirms the assumption of the existence of various fragmentation mechanisms, including the method of breaking drops under the action of intense sound waves caused by the collapse of vapor formations. The results of numerical estimates are given, which indicate that the rate of cooling of particles formed in the process of fragmentation can reach values from 109 to 1010 K/s. These values are quite sufficient for obtaining various alloys with an amorphous structure. The possibility of destruction of vapor shells around hot drops under the action of pressure pulses caused by the collapse of adjacent vapor-gas formations has been experimentally confirmed.