Cr、Mn、Co、Ni掺杂对Al13Fe4相稳定性和力学性能影响的第一性原理研

采用基于密度泛函理论的第一性原理计算方法，系统地研究了不同掺杂浓度下过渡族元素Cr、Mn、Co、Ni在Al13Fe4相中的占位情况、结构稳定性和机械性能. 计算得到所有的Al13(Fe24-xMx) (M=Cr、Mn、Co、Ni；X=1，2，4)相都具有良好的热力学稳定性和机械稳定性. 相同掺杂浓度化合物的形成焓按如下顺序减小：Al78(Fe24-xCrx) > Al78(Fe24-xMnx) > Al13Fe4 > Al78(Fe24-xNix) > Al78(Fe24-xCox).形成焓的降低增加了Al13Fe4相成核驱动力，Co和Ni有利于促进Al-Fe合金中Al13Fe4相形核，细化Al13Fe4相. 过渡族元素可以改善金属间化合物的脆性，增强塑性变形能力. 并且随着掺杂浓度的增加，过渡族元素的加入对脆性的改善呈先增大后减小的趋势.

The effect of Cr, Mn, Co, and Ni on stability and mechanical properties of the Al13Fe4 phase from first-principles

Al13Fe4 intermetallic compounds were systematically studied using first-principles methods based on the addition of 3d transition elements M (M = Cr, Mn, Co, Ni) on different substitution sites with different doping concentrations. It is found that Al78(Fe24-xMx) compounds can be formed and that the crystal structure is thermodynamically stabile. The formation enthalpy of compounds with the same concentration decreases according to the following order: Al78(Fe24-xCrx) > Al78(Fe24-xMnx) > Al13Fe4 > Al78(Fe24-xNix) > Al78(Fe24-xCox). The reduction of formation enthalpy increases the nucleation driving force. This suggests that Co and Ni are the most suitable elements for stimulating the nucleation of the Al13Fe4 phase in Al-Fe alloys. M elements can improve the brittleness of intermetallic compounds and enhance the plastic deformation ability. As the doping concentration increases, the brittleness improvement through the addition of M elements is found to firstly increase and subsequently to decrease.