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基于典型微观凝固单元体内的溶质质量守恒,结合前人的研究工作,建立了一个适合于枝晶凝固方式的二元合金微观偏析半解析模型.本模型同时考虑了反向扩散和粗化对微观偏析的影响,并对枝晶臂间距的粗化直接进行计算,因此更为精确.若只考虑反向扩散的影响,本模型可以简化为BF模型形式;而如果只考虑粗化的影响,本模型可简化为Mortensen模型.本模型完整地统一了以BF模型为代表的反向扩散类模型和以Mortensen模型为代表的粗化模型.利用本模型同样可以对多元合金的微观偏析进行很好预测.以Fe-C-X(Si,Mn,P,S)合金体系为例对本模型的求解过程进行了详细的阐述.本模型可以很好地预测Al-4.9%Cu二元合金的共晶分数以及Fe-C-X(Si,Mn,P,S)多元合金体系的零强度温度和零塑性温度,并与实测值吻合良好.
Based on the conservation of solute mass in typical microscopic solidification units, a semi-analytical model for the micro-segregation of binary alloys suitable for dendrite solidification was established based on the previous studies. The model also considers the effects of reverse diffusion and coarsening on microscopic Segregation, and dendrite arm spacing roughening directly calculated, and therefore more accurate.If only consider the impact of reverse diffusion, the model can be simplified as the BF model form; and if only consider the impact of coarsening, the The model can be simplified as the Mortensen model.The model completely unifies the inverse diffusion model represented by the BF model and the coarsening model represented by the Mortensen model.The model can also predict the microsegregation of the multi-element alloy well The process of this model is described in detail by taking the Fe-CX (Si, Mn, P, S) alloy system as an example.The model can well predict the eutectic fraction of Al-4.9% -CX (Si, Mn, P, S) zero alloy temperature and zero plasticity temperature, and with the measured value in good agreement.