微合金化元素对Fe-Al界面结合的第一性原理研究

First-principles studies of the effects of microalloy elements on Fe/Al interface

利用第一性原理中的DFT理论研究了Fe/Al界面的能量学和电子结构,讨论了替位型掺杂的元素Zn、Mn、Ni在Fe/Al界面处的作用.结果表明:元素Zn、Mn、Ni都会优先替换界面处的Fe原子,使得界面结合能增加,体系更稳定,有利于界面的结合;跨界面的Fe原子与Al原子之间的电荷布居、键长以及差分电荷密度图的计算表明:掺杂后有利于跨界面的Fe-Al间成键,从而加强了Al层与Fe基体的结合,且结合强度由强到弱依次为:掺Zn>掺Mn>掺Ni;与实验比较吻合.最后对掺杂Zn的增韧机理加以解释.

DFT of first-principles was used to study the energy and electronic structure Fe/Al interface. The interfaces of Fe/Al substituted by Zn Mn Ni were investigated. Result shows that after adding Zn Mn Ni to the interface, they will replace Fe atom priorily resulting in the strengthens of interface energy, and the system is more stable. The calculation of charge population, bond length and difference electric-charge density between Fe and Al atoms show that the bond between Fe and Al will be enhanced after doping that can lead to the intensification of AI and Fe with its order of Zn Mn Ni from strong to weak, which are in accordance with the experiments. Then toughening mechanism owing to Zn was discussed.