Investigation on AlP as the heterogeneous nucleus of Mg2Si in Al–Mg2Si alloys by experimental observation and first-principles calculation
Investigation on AlP as the heterogeneous nucleus of Mg2Si in Al–Mg2Si alloys by experimental observation and first-principles calculation
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Al-Mg2Si合金中AlP作为Mg2Si异质核的实验观察和第一性原理计算研究
DOI：
10.1016/j.rinp.2017.11.025
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发表时间：
2018
影响因子：
5.3
通讯作者：
Liu Yongchang
中科院分区：
文献类型：
--
作者：
Sun Jiayue;Li Chong;Liu Xiangfa;Yu Liming;Li Huijun;Liu Yongchang
利用扫描电镜观察了Al-20%Mg2Si和Al-3%P中间合金中初生Mg 2Si的组织演变。采用第一性原理计算方法研究了AlP/Mg 2Si界面的界面性质。计算结果表明，AlP（1 0 0）/Mg 2Si（2 1 1）和AlP（3 3 1）/Mg 2Si（1 1 0）界面可以稳定形成。P端AlP（100）/Mg 2Si（211）界面具有最大的粘附功（4.13J/m2），理论上是最稳定的。界面电子结构表明，AlP与Mg 2Si之间存在Si-Al、Si-P和Mg-P共价键。由于AlP颗粒作为Mg 2Si的有效异质形核，初生Mg 2Si颗粒由枝晶转变为八面体/截八面体，其尺寸减小到~ 20 μm。
The microstructural evolution of primary Mg2Si in Al–20%Mg2Si with Al–3%P master alloy was observed by scanning electron microscope. And the interfacial properties of AlP/Mg2Si interface were investigated using first-principles calculations. The calculation results show that AlP(1 0 0)/Mg2Si(2 1 1) and AlP(3 3 1)/Mg2Si(1 1 0) interfaces can form steadily. P-terminated AlP(1 0 0)/Mg2Si(2 1 1) interface with the largest work of adhesion (4.13 J/m2) is theoretically the most stable. The interfacial electronic structure reveals that there are covalent Si–Al, Si–P and Mg–P bonds existing between AlP and Mg2Si slabs. Due to the AlP particles as effective heterogeneous nucleus of Mg2Si, primary Mg2Si particles change from dendrite to octahedron/truncated octahedron, and their sizes decrease to ∼20 μm.