等流速下新型脉冲磁场对纯铝凝固组织的影响

Effect of New Pulsed Magnetic Field on Solidification Structure of Pure Aluminum at Constant Flow Rate

以工业纯铝为研究对象,采用凝固试验、数值模拟和理论分析相结合的方法,研究了等流速条件下新型脉冲磁场作用下电流强度与周期组合对纯铝凝固组织的影响。结果表明:新型脉冲磁场能明显细化纯铝凝固组织,并且流速相同情况下纯铝凝固组织细化效果并不相同。在无隔离网条件下,通过数值模拟分析发现电磁力密度方向主要指向熔体内部,并且熔体主要受电磁力峰值作用使液面发生振荡从而产生大量晶核。在有隔离网条件下,通过动力学分析认为晶核受时均电磁力作用下晶核穿过边界层进入熔体促使晶粒增殖是晶粒细化的主要原因。

Taking industrial pure aluminum as the research object, the effects of the combination of current intensity and cycle on the solidification structure of pure aluminum under the action of a new pulsed magnetic field at constant flow rate were studied by means of solidification experiment, numerical simulation and theoretical analysis. The results show that the new pulsed magnetic field can obviously refine the solidified structure of pure aluminum, and the refining effect of solidified structure of pure aluminum is different under the same flow rate. Under the condition of no isolation net, through numerical simulation analysis, it is found that the direction of electromagnetic force density mainly points to the interior of the melt, and the liquid level oscillates due to the peak value of electromagnetic force, resulting in a large number of nuclei. Under the condition of isolation net, through dynamic analysis, it is considered that the grain is mainly affected by time averaged electromagnetic force, and the grain entering the melt through the boundary layer to promote grain proliferation is the main reason for grain refinement.