建立偏晶合金难混溶区凝固过程的两相数学模型,模拟研究了有、无磁场Al-10%Bi过偏晶合金微观组织演变,研究了温度、速度、第二相体积分数等物性参数对凝固组织宏观偏析的影响.结果表明,在磁场作用下温度场为中心对称分布,更有利于第二相液滴的均匀分布;电磁力抵消了部分重力和Marangoni力,使无磁场时外环流的速度场变为有磁场时斜向下的速度场,且速度明显降低,从而减轻了强对流导致的重力偏析;在磁场的作用下,试样底部第二相的体积分数减小,凝固组织宏观偏析得到改善.
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