Numerical analysis for solid-liquid interface shape at various temperature gradient in electromagnetic cold crucible directional solidification

Abstract

The straight solid-liquid (S-L) interface is necessary for obtaining a directional solidification ingot with industrial size and well directional solidification in electromagnetic cold crucible directional solidification (CCDS). Overheating and lateral heat dissipation are the significant parameters for the straight S-L interface in CCDS. In this paper, Nb-16Si-22Ti as an example was used for analyzing the influence of temperature gradient and boundary conditions on the shape of S-L interface by Comsol Multiphysics software. A 3-D parametric geometry as original proportional model was established and the accuracy of the model was verified by measuring magnetic flux density norm with small coil method. The simulation results exhibit that the shape of S-L interface formed by 50kHz-2400A is closer to the plane and beneficial to gain directional grain. The heat supplement meets the requirement of heat loss with 50kHz, and there is little difference for temperature gradient in both solid and liquid interface. The axial and radial maximum temperature gradient of 50 kHz-2400 A is 61.46 K/mm and 63.84 K/mm, respectively.