The Angular Velocity as a Function of the Radius in Molten Ga75In25 Alloy Stirred Using a Rotation Magnetic Field

The simulation of the solidification of alloys (like steel or aluminium alloys), which is carried out by using the melt flow induced by a rotation magnetic field (RMF), needs the correct angular velocity vs. the radius function of the melt. Because it is impossible to directly obtain information about the melt flow from industrial casting, this information can only be obtained from well-monitored experiments using low-melting-point metals or alloys (e.g., Hg, Ga, GaIn, and GaInSn). In this work, we first summarized the measuring methods that are suitable for determining this function and analysed their advantages and disadvantages. All of them disturb, to some degree, the melt flow, except for the Pressure Compensation Method (PCM); therefore, this method was used in the experiments. Closed TEFLON crucibles with a 60 mm length and 12.5 mm radius and Ga75wt%In25wt% alloy was used. The angular velocity (omega) was calculated from the compensation pressure measured at r = 5, 7.5, 10, and 12.5 mm in the 0-90 mT range of magnetic induction, B. Based on the omega(B, r) dataset, a suitable omega(B, r) function was determined for the simulation.