FeAl(B2) 合金La, Ac, Sc 和 Y 元素微合金化的第一性原理研究

采用基于密度泛函理论的第一性原理计算方法, 研究了稀土元素(La, Ac, Sc 和 Y) 微合金化对FeAl (B2) 有序金属间化合物合金晶体结构、 弹性和电子性能的影响. 计算结果表明: 稀土元素Y 易于取代Fe位, 而Sc, La和Ac易于取代Al位, 其中Ac元素的加入使晶格点阵发生最大的变形. 弹性性能的计算表明La, Ac, Sc 和 Y 元素的加入可以改善FeAl (B2) 的塑性, 其中Fe₇Al₈Sc具有最好的塑性和硬度. 稀土元素对合金性能的影响, 主要是由于稀土原子的加入改变了Fe和Al电子之间的杂化作用. 计算结果与已有的试验结果和理论结果相一致.

First-principles study of FeAl(B2) microalloyed with La, Ac, Sc and Y

The effects of FeAl(B2) microalloyed with rare earth element (REEs) La, Ac, Sc and Y on structural, elastic and electronic properties are investigated by first-principles calculation based on the density function theory (DFT). The calculation results show that the REEs Y tend to be substituted for Fe site, while La, Ac and Sc tend to be substituted for Al site, and Ac causes the largest lattice distortion. The calculation results of elastic properties show that the ductility of FeAl(B2) is improved by the addition of La, Ac, Sc and Y. The Fe₇Al₈Sc has better ductility and hardness. The effect of REEs on the performance of alloy is attributed to the variation of hybridization between Fe and Al electrons. The calculation results are in accordance with experimental and theoretical results.