Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, USA.
Phys Rev Lett. 2010 Aug 13;105(7):076102. doi: 10.1103/PhysRevLett.105.076102.
By employing a combination of three-dimensional atom-probe tomography and first-principles calculations, significant qualitative and quantitative differences in solute segregation at coherent and semicoherent interfaces bounding a single θ^{'} precipitate in an Al-Cu-based alloy are found. Qualitatively, localized segregation is observed at the semicoherent interface, whereas delocalized behavior is present at the coherent facets. Quantitatively, segregation at the semicoherent interface is a factor of 2 greater than at the coherent interface, resulting in a decrease in interfacial energy that is more than 5 times greater than that observed at the coherent facet. These observations illustrate unambiguously the strong couplings among interface structure, chemical composition, and energetics.
采用三维原子探针断层成像术和第一性原理计算相结合的方法，在一个基于 Al-Cu 的合金中边界单个θ'析出相的完全共格和半共格界面处，溶质偏析在定性和定量方面都存在显著的差异。定性上，在半共格界面上观察到局部偏析，而在共格晶面则呈现出弥散行为。定量上，半共格界面上的偏析比共格界面大 2 倍，导致界面能降低，比在共格晶面观察到的降低程度大 5 倍以上。这些观察结果明确地说明了界面结构、化学成分和能量之间的强耦合。
