Electric current pulse driven liquid metal flow studied by the multi-dimensional Ultrasound Doppler array technique

The electric current pulse (ECP) technique is an effective method of applied MHD to be used for promoting grain refinement in the macrostructure of metal alloys during the solidification process. However, the physical mechanism of the ECP grain refinement technique has not been fully understood until now because of a shortage of knowledge of the forced flow induced by current pulses. In a comprehensive study, experimental investigations were performed considering the configuration of two parallel electrodes immersed through the free surface into a liquid metal column of GaInSn. A melt flow is driven by the Lorentz force resulting from an interaction of the electric current between the electrodes and its induced magnetic field. By means of the ultrasonic Doppler array technique the time-dependent flow field structure induced by DC and pulsed currents under various conditions and parameters was investigated. The measuring results of the study will be presented and discussed.