The Use of Steady Electromagnetic Fields to Control the Columnar Solidification of Binary-Metal Alloys

This article considers the nondirectional solidification of a binary-metal alloy in a cylindrical cavity, which is cooled along its outer vertical wall and the bottom. To study the influence of convection within the liquid phase on the final segregation, three cases are examined: the purely buoyancy-driven convection (case 0), the impact of an external steady axial magnetic field on the melt flow during solidification (case 1), and the effect of the combination of an external magnetic field with a steady electrical current (DC) applied directly to the melt (case 2). The results show that convection in the form of multivortices caused by the thermosolutal buoyancy leads to macrosegregations in the form of V-channels. The application of an external axial magnetic field alone suppresses the multivortex structure and, thus, the macrosegregation. By contrast, the parallel use of an additional voltage of 10⁻³ V leads to an increase in final macrosegregation.