Intensive emission of droplets during melting of metal samples in a high-frequency inductor

The results of experimental and computational studies of the processes accompanying the melting of metal samples heated in air using induced currents are presented. The materials used for the experimental models–spheres and cylinders with a characteristic size of $10$ mm–were pure iron, nonferrous metals, and various grades of steel. An unusual physical effect observed in experiments with iron and steels and associated with the intense release of sparks from the samples was studied: small brightly glowing metal droplets. A possible thermomechanical mechanism for the emission of droplets is proposed, based on the occurrence of excess melt pressure during metal melting inside the volume of the sample, limited by the resulting solid shell consisting of iron oxides. Numerical calculations were carried out, the results of which generally confirm the hypothesis presented.