中文摘要：

应用CAFE法与实验相结合的方法，对Mg-Y-Zn-Mn-Ca合金凝固组织进行了模拟研究，确定出了该合金凝固组织模拟的数学模型，同时研究了形核参数（ΔTv,max、ΔTv,σ、nv,max）对合金凝固组织的影响.结果表明，ΔTv,max越大，nv,max越小，晶粒生长越粗大，ΔTv,σ主要控制晶粒的大小区域，随着其增大，大晶粒区域增加.当形核参数分别为ΔTv,max=10K、ΔTv,σ=1K、nv,max=2×1013m-3时，模拟得到的凝固组织几乎全部为细小的等轴晶，晶粒平均尺寸为约32.25μm，实验中得到的晶粒平均尺寸约为29.76μm.计算得到的凝固组织与实验结果基本吻合.

英文摘要：

Effect of nucleation parameters(ΔT v,max、ΔT v.σ、n v,max)on solidifi cation structure of Mg-Y-Zn-Mn-Ca alloy was investigated based on CAFE method combined with experiment,and determined the mathematical model of solidification microstructure simulation.It was shown that with theΔT v,max increasing and n v,max decreasing,the grain would be large.TheΔT v.σmainly controled the rigion of grain size.The bigger the value ofΔT v.σ,the more large grain region.The simulation showed that almost all solidifi cation structure of the sample was equiaxed grains when the nucleation parameters wasΔT v,max=10K,n v,max=2×1013m-3,ΔT v.σ=1K,and the average grain diameter was32.25μm.The average grain diameter of laboratory sample was29.76μm.The solidifi cation structure by calculation was the same as that of the experiment results.