Review of gas atomisation and spray forming phenomenology

Gas atomisation phenomenology of liquid metals and alloys is both intriguing and instructive. Predating atomistic studies of melt disintegration by almost three decades, it provides a functional means of correlation between drop sizes and processing parameters, as is the case in liquid metal spray forming. In this article a concise but thorough compilation of melt disintegration phenomenology is provided, with emphasis on high pressure gas atomisation, inclusive of notation on mean particle diameters, the role of viscosity, density and other dimensionless ratios that enter as variables in high pressure gas atomization and spray forming, as well as break up of a liquid column and theories of drop disintegration in flight. The article concludes by introducing the very efficient Surface Wave Formation principle which facilitates the treatment of complex atomisation geometries and turbulent regimes.