Abstract: Electromagnetic stirring can be used in direct chill casting processes, in order to refine the cast microstructures, as well as to improve the surface quality of the Aluminum castings. The present paper reports on the effect of Rotary Electromagnetic Stirring (Rotary-EMS) on the cast microstructure of two different aluminum alloys, A356 and AA2024. Along with the casting experiments, a numerical model was developed in order to calculate the external Lorenz forces created within the ceramic crucible during electromagnetic stirring of the melt. The magnetic flux distribution was predicted by solving the Maxwell equations and then validated through previous experimental results. According to the casting experiments, the rotating magnetic field has a positive influence on the refinement of the dendritic structure of A356 samples. Similarly, electromagnetic stirring of AA2024 melt during solidification, helped in the homogenization of the alloying element distributions at both the micro and macro scales.
Authors: M. Mahdi Aboutalebi, Mihaiela Isac, and Roderick I. L. Guthrie
Keywords: Aluminium Alloys, Solidification Microstructure, Computational Modelling, Electro-Magnetic Stirring (EMS)