临界晶核半径

外加强磁场提高了Si和Al-Si的自由能，相对降低了Si形核势垒和临界晶核半径，促进了初晶硅和共晶Al-Si组织细化。

It will decrease the potential barrier and critical grain radius comparatively . Magnetic field will induce the refinement of primary Si and eutectic Al-Si alloy .

根据经典成核理论，利用诱导期数据计算了KDP过饱和溶液的固-液界面张力、临界晶核半径等成核参数，并与理论计算值进行比较。

The interfacial tension and critical radius of nuclei were calculated basing on the induction period data by using the classical nucleation theory .

利用凝固过程热力学理论研究了铁液洁净度与过冷度、凝固热力学驱动力、形核功和临界晶核半径等的关系。

The relationship between the cleanness of liquid iron and undercooling , thermodynamic driving force of nucleation , the activation energy to form a crystal nucleus and the critical radius of nucleus has been investigated in terms of thermodynamics in solidification .

结果发现，随着洁净度的提高，高洁净钢和纯铁凝固的过冷度增加，形核功降低，临界晶核半径变小，形核率增大，凝固组织中晶粒的数量增加，晶粒得到细化。

The results showed that undercooling degree increased , the nucleation energy decreased , the critical radius of nucleus become smaller , the nucleation ratio and nucleation number increased , and the grain size become finer with the improvement in cleanness of melt .