Morphology, thermal stability, electronic structure and mechanical properties of α-AlFeMnSi phases with varying Mn/Fe atomic ratios: Experimental studies and DFT calculations
Morphology, thermal stability, electronic structure and mechanical properties of α-AlFeMnSi phases with varying Mn/Fe atomic ratios: Experimental studies and DFT calculations
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不同Mn/Fe原子比的α-AlFeMnSi相的形貌、热稳定性、电子结构和机械性能：实验研究和DFT计算
DOI：
10.1016/j.jallcom.2021.163523
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发表时间：
2022
影响因子：
6.2
通讯作者：
Haitao Zhang
中科院分区：
文献类型：
--
作者：
Xiaozu Zhang;Dongtao Wang;Hiromi Nagaumi;Yunxuan Zhou;Wei Yu;Xiaoyu Chong;Xinzhong Li;Haitao Zhang
分离含铁金属间化合物是降低铝硅合金中铁含量的有效方法。含铁金属间化合物的三维形貌和稳定性是影响其分离效率的重要参数。结合实验和第一性原理计算，研究了α-AlFeMnSi的三维形貌、稳定性、电子结构和力学性能随Fe/Mn原子比的变化规律。实验结果表明，随着Mn/Fe原子比的增加，α-AlFeMnSi的三维形貌由汉字转变为正多面体，且α-AlFeMnSi相均具有立方晶体结构。计算的混合焓值表明，α-AlFeMnSi相均为负值，在热力学上是稳定的。电子结构和Mulliken种群计算表明，Mn/Fe比的变化导致Si-Mn、Si-Fe、Al-Mn和Al-Fe的化学键的整体变化，从而导致α-AlFeMnSi相的稳定性和力学性能的演变。力学性能计算结果表明，α-AlFeMnSi相的杨氏模量和硬度随Mn/Fe原子比的增加而提高，纳米压痕实验也证实了这一点。这些结果为设计易分离的含铁金属间化合物提供了成分指导，并试图解释α-AlFeMnSi相性能演化的物理机制。
Separation of Fe-containing intermetallics is an effective method to decrease Fe content in Al-Si alloys. The three-dimensional (3D) morphology and stability of Fe-containing intermetallics are important parameters affecting their separation efficiency. Combined with experiments and first-principles calculations, the variation of 3D morphology, stability, electronic structure and mechanical properties of α-AlFeMnSi are studied with the evolution of Fe/Mn atomic ratio. The experimental results show that the 3D morphology of α-AlFeMnSi transforms from Chinese character to regular polyhedron with the increment of Mn/Fe atomic ratio and all α-AlFeMnSi phases have cubic crystal structure. The calculated mixing enthalpies indicate that all α-AlFeMnSi phases are stable in thermodynamics due to the negative values. The electronic structure and Mulliken population calculations show that the variation of Mn/Fe ratio results in the overall change of chemical bondings of Si-Mn, Si-Fe, Al-Mn and Al-Fe, which leading to the evolution of stability and mechanical properties of α-AlFeMnSi phases. The calculated results of mechanical properties demonstrate that the Young’s modulus and hardness of α-AlFeMnSi phases are improved with the increment of Mn/Fe atomic ratio, which is also validated by nano-indentation measurements. These results provide the componential guidance about designing easy-separable Fe-containing intermetallics and try to explain physical mechanism of property evolution of α-AlFeMnSi phase.