稀土元素Sc、Y掺杂对α-Fe力学性能影响的第一性原理计算

First-principles Calculation of Effects of Rare Earth Elements Sc and Y Doping on Mechanical Properties of α-Fe

采用基于密度泛函理论的第一性原理方法,从原子尺度研究了稀土元素Sc、Y掺杂对a・Fe力学性能的影响。结果表明,掺杂稀土元素会降低a・Fe的弹性常数及弹性模量,但会提升其韧性。掺杂稀土元素能很大程度降低a-Fe的广义层错能,使a-Fe的塑性得到提升。总的来说,稀土元素Sc、Y固溶于a・Fe,会使其强度降低、韧性提升,其中Y元素的作用效果相对更强。

The first-principles method based on density functional theory was used to study the effect of rare earth Sc andY doping on the mechanical properties of a・Fe from atomic scale. The results show that doping rare earth elements candecrease the elastic constant and elastic modulus of Fe, but it increase its toughness. The doped rare earth element cangreatly reduce the generalized stacking fault energy of a-Fe, which can improve its plasticity. In general, when the rare earthelement Sc and Y are dissolved into a-Fe, the strength of a-Fe reduces, but the toughness improves, and the effect of Yelement is relatively stronger.