Effect of the solidification front velocity on the microstructure of the eutectic in a hypereutectic Al-Si alloy

The aluminium-silicon (Al-Si) alloys are widely used, and in combination with the appropriate mechanical properties, they are attractive raw materials even for the automobile and aircraft industries. Its eutectic has an irregular structure, which makes its classification challenging. The silicon phase of the eutectic has a lamella morphology, which can be modified by various interventions. Their microstructure can be influenced by changes in solidification parameters, such as flows induced by a rotating magnetic field (RMF), changes in the movement velocity of the solidification front, and changes in the temperature gradient. During our work, we dealt with an Al–Si 18% hypereutectic alloy stirred (7.2 mT) and not stirred by the rotating magnetic field. The experiments were performed at different sample moving velocities, and the eutectic of the samples was examined using image analysis software.