Distributions of Electromagnetic Fields and Forced Flow and Their Relevance to the Grain Refinement in Al–Si Alloy Under the Application of Pulsed Magneto-Oscillation

Abstract

Distributions of electromagnetic fields and induced forced flow inside a metal melt are crucial to understand the grain refinement of the metal driven by pulsed magneto-oscillation (PMO). In the present study, PMO-induced electromagnetic fields and forced flow in Ga-20wt%In-12wt%Sn liquid metal have been systematically investigated by performing numerical simulations and corresponding experimental measurements. The numerical simulations have been confirmed by magnetic and melt flow measurements. According to the simulated distribution of electromagnetic fields under the application of PMO, the strongest magnetic field, electric eddy current and Lorentz force with inward radial direction inside the melt are concentrated adjacent the sidewall of cylindrical melt at the cross section of middle height of coil. As a result, a global forced flow throughout the whole cylindrical column filled with Ga-20wt%In-12wt%Sn melt is initiated with a flow structure of two pair of symmetric vortex ring. The PMO-induced electromagnetic fields and forced flow in Al-7wt%Si melt have been numerically simulated. The contribution of electromagnetic fields and forced flow to the grain refinement of Al-7wt%Si alloy under the application of PMO is discussed. It indicates that the forced flow may play a key role in the grain size reduction.

Optimization of Process Parameters for 40Cr Steel Continuous Casting Round Bloom with Pulsed Magneto‐Oscillation Treatment

“…The numerical simulation-aided process design for continuous casting is particularly important, and great progress has been made in numerical simulation of PMO in recent years. [23][24][25][26] Gong et al [27] obtained the relationship between electromagnetic force and critical nucleation radius by simulating the electromagnetic field and flow field in the molten metal and combining it with theoretical calculations. Xu et al [25,26] measured the melt flow rate by an ultrasound Doppler velocimetry, and verified the numerical simulation of the flow field of Ga-In-Sn liquid metal treated by PMO.…”

“…[23][24][25][26] Gong et al [27] obtained the relationship between electromagnetic force and critical nucleation radius by simulating the electromagnetic field and flow field in the molten metal and combining it with theoretical calculations. Xu et al [25,26] measured the melt flow rate by an ultrasound Doppler velocimetry, and verified the numerical simulation of the flow field of Ga-In-Sn liquid metal treated by PMO. By simulating the electromagnetic and flow fields within the melt under the combined magnetic field formed by PMO and a static magnetic field, Zhu et al [28] observed a single-loop structure in the melt flow parallel to the static magnetic field and a double-loop structure in the melt flow perpendicular to the static magnetic field.…”