Solidification of aluminium alloys under the influence of modulated magnetic fields


Solidification of aluminium alloys under the influence of modulated magnetic fields

Eckert, S.; Willers, B.; Räbiger, D.; Dong, J.; Nikrityuk, P. A.; Eckert, K.

AC magnetic fields are used in industrial practice for melt stirring. The requirements are manifold for miscellaneous metallurgical operations or casting technologies, mainly the magnetic field application should provide an efficient mixing of the melt in order to achieve homogeneous distributions of solute and/or temperature. The rotary stirring during solidification has been proved to be a striking method to achieve a purposeful alteration of the microstructure of casting ingots, such as a distinct grain refining or the promotion of a transition from a columnar to an equiaxed dendritic growth (CET). Solidification experiments as well as numerical simulations were carried out considering the directional solidification of Al-Si alloys from a water cooled copper chill. A modulated rotating magnetic field (RMF) was applied for melt agitation. Thermocouples were used to measure the temperature field during solidification. The velocity field in the liquid phase was determined by means of Ultrasound Doppler velocimetry (UDV). The comparison between numerical simulations and solidification experiments delivered a good agreement. Our results demonstrate that the modulated magnetic field enables an effective control of the flow field and the structure of the solidified samples.

Keywords: solidification; aluminium alloys; electromagnetic stirring; modulated magnetic fields; macrosegregation

  • Lecture (Conference)
    11th International Conference on Aluminium Alloys, 22.-26.09.2008, Aachen, Germany
  • Contribution to proceedings
    11th International Conference on Aluminium Alloys, 22.-26.09.2008, Aachen, Germany, 497-502

Permalink: https://www.hzdr.de/publications/Publ-11199
Publ.-Id: 11199