Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

This study aims to investigate how pulsed electromagnetic fields (PEMF) can affect grain refinement and microstructure during the solidification of a model Ga-In alloy. The magnetic system used generates field intensities of 8 - 11 mT and frequencies in the domain between 10 and 300 Hz, a duty cycle of 50%. We record the dendritic structures at the end of solidification experiments after switching OFF the electromagnetic field via X-ray radiographic imaging. Preliminary lab-scale results show that the solidification under frequencies above 100 Hz leads to dendrite fragmentation and solute redistribution in the mushy zone. No evidence of a CET is observed despite numerous fragmentation events. The fragments that detached from the dendritic network were unable to grow as equiaxed dendrites in the liquid as they became trapped within the dendritic network.