电场对电磁冷坩埚定向凝固磁场与温度场研究

Research on magnetic field and temperature field ofelectromagnetic cold solidification

脉冲电流作用定向凝固不仅能影响晶体的生长,还可调控凝固组织,从而影响合金的性能。为进一步研究其作用机理,采用ANSYS有限元软件模拟脉冲电流作用下合金熔体的电磁场分布以及对TiAl基合金连续凝固温度场的影响。结果表明:脉冲电流作用下的合金熔体表层磁感应强度最大,径向随着与表层距离的增大,磁感应强度下降。随着脉冲电流强度的增大,由于脉冲电流产生的集肤效应与焦耳热效应,使温度场与电磁场整体提高,轴向感应线圈中部温度最高,径向合金熔体与表层温差值逐渐减小、温度分布更均匀,侧向散热减弱,定向凝固趋势提升。

The action of pulse current on directional solidification process can not only affect the growth of crystal but also regulate the solidification structure,thus affecting the properties of the alloy.To further study its mechanism,the electromagnetic field distribution of the alloy melt under the action of pulse current and the effect on the temperature field of the continuous solidification experiment of TiAl base alloy are simulated by ANSYS.The result shows that:the surface magnetic induction intensity of the alloy melt under the action of pulse current is the largest and the radial magnetic induction intensity decreases with the increasing distance from the surface layer.With the increase of pulse current intensity,due to the skin collection effect of the pulse current and the Joule thermal effect,the overall temperature of the temperature field and electromagnetic field improves,the temperature in the middle of the axial induction coil is the highest.The temperature difference between the radial alloy melt and the surface layer is gradually reduced,the temperature distribution is more uniform,the lateral heat dissipation is weakened,and the directional solidification trend increases.