(沈阳工业大学 材料科学与工程学院， 沈阳 110023)
摘 要: 根据分子动力学理论建立液态ZA27合金的原子集团， 结合计算机编程构造出ZA27合金α相与液相共存时的原子构形及α相大角度重位点阵晶界模型。 利用递归法计算铁、 稀土元素固溶于晶粒内、游离于固液相界面及其在α相晶界处的环境敏感镶嵌能。结果表明： 铁、 稀土处于固液相界区比在晶内更稳定， 这解释了铁、 稀土在α相内溶解度很小， 结晶时富集于固液相界前沿液体中， 从而导致凝固结束后铁、 稀土元素偏聚于晶界，并形成成分复杂的稀土化合物的事实。
关键字: 稀土; 晶界; 递归方法; 电子结构
（College of Materials Science and Engineering，
Shenyang University of Technology， Shenyang 110023， China）
Abstract: A model of liquid ZA27 casted alloy was established according to molecular dynamics. An atomic structural model of α phase and liquid co-existence and α phase large-angle superposition lattice crystal-boundary was also presented by means of computer programming. The recursion method was adopted to calculate the circumstance sensitivity embed energy of rare earth(RE) and iron in grains, crystal boundaries and phase boundaries, respectively. The calculation shows that RE and iron are more stable in phase boundaries than in grains, which explains the fact that the solution of RE and iron in α phase is small and they are affluent ahead of phase boundary, leading to RE and iron atoms congregating on the crystal boundaries and forming complicated RE-compound.
Key words: rare earth; crystal boundary; recursion method; electronic structure
