Non-Equilibrium Solidification, Modeling for Microstructure Engineering of Industrial Alloys (NEQUISOL)

Kurzfassung

Within the ESA-MAP project NEQUISOL solidification and microstructure evolution of containerless undercooled drops and droplets of Al-based alloys are investigated. Individual drops in diameter of about 6mm are processed by electromagnetic levitation both on Earth and in Space. This technique allows to measuring the temperature time profile during melting and solidification yielding the undercooling prior to solidification. The dendrite growth velocities are measured by high-speed camera technique. Comparing experiments on Earth and in Space allows for determining the influence of convection on solidification kinetics and microstructure evolution. These results are used to extend multi-scale modeling to predict microstructure development as function of undercooling and cooling rate. The results are directly related to the production of Al-Ni powders in atomization facilities operated by some partners of the project. Atomization provides both containerless processing and reduced gravity conditions in solidification of small droplets during free fall on Earth. It is an industrial production route of advanced materials.