A thermomechanical model for the fragmentation of a liquid metal droplet cooled by water

• Published in: Journal of physics. Conference series 2017-11, Vol.891 (1), p.12130
• Main Authors: Ivochkin, Yu P, Monastyrskiy, V P
• Format: Article
• Language: English
• Subjects: Cold water; Continuous casting; Droplets; Fragmentation; Liquid metals; Physics; Qualitative analysis; Solid phases; Steam jets; Tensile stress; Thermomechanical analysis; Thin walled shells
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/891/1/012130

A thermo mechanical aspect of the fragmentation of a liquid metal droplet, solidified as it falls into cold water, is considered in the presented model. The formation of a solid phase in the form of continuous, fluid-tight and relatively rigid casting skin results in a pressure decrease inside the droplet due to the difference between liquid and solid metal density. Because of the high compression modulus of the melt, the pressure in the droplet becomes negative when the thickness of the solid skin achieves several microns. The tensile stress in the melt results in the deformation of the casting skin or the melt's continuity violation in the form of a shrinkage pore. The rupture of the deformed solid crust results in the penetration of steam jets into the liquid part of the drop. Due to the difference in pressure in the surrounding steam and in the droplet, the casting skin is crushed and the melt is blown out. Both scenarios contribute to the hydrodynamic destruction of the droplet. The suggested thermo mechanical model gives a qualitative explanation for experimental data. In the experimental part of the work, droplets of molten Sn were solidified in water. The solidified pieces of the droplets usually include deformed, thin-walled shells and dispersed particles. On a qualitative level the composition and shape of the solid fragments can be explained within the bounds of the suggested thermo mechanical model.