Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Phys Rev Lett. 2015 Aug 7;115(6):065501. doi: 10.1103/PhysRevLett.115.065501. Epub 2015 Aug 3.
Density-functional-theory calculations of twin-boundary energies in hexagonal close packed metals reveal anomalously low values for elemental Tc and Re, which can be lowered further by alloying with solutes that reduce the electron per atom ratio. The anomalous behavior is linked to atomic geometries in the interface similar to those observed in bulk tetrahedrally close packed phases. The results establish a link between twin-boundary energetics and the theory of bulk structural stability in transition metals that may prove useful in controlling mechanical behavior in alloy design.
利用密度泛函理论计算六方密堆积金属中孪晶界能，发现元素 Tc 和 Re 的数值异常低，通过与降低每个原子电子数的溶质合金化，可以进一步降低其数值。这种异常行为与界面中的原子几何形状有关，类似于在体心四面体型密堆积相中观察到的原子几何形状。研究结果在孪晶界能和过渡金属体相结构稳定性理论之间建立了联系，这可能在控制合金设计中的力学行为方面具有重要意义。
