Advanced Materials Laboratory, Department of Materials Science and Engineering, Tsinghua University, Beijing, China.
J Phys Chem B. 2011 Apr 28;115(16):4703-8. doi: 10.1021/jp200082e. Epub 2011 Apr 7.
For the Cu-Zr-Ni system, an interatomic potential was constructed under the newly proposed formulism named smoothed and long-range second-moment approximation of tight-binding. Applying the constructed potential, molecular dynamics simulations were carried out to compare the relative stability of crystalline solid solution versus its disordered counterpart. Simulations not only reveal that the origin of metallic glass formation is the crystalline lattice collapsing while the solute concentrations exceed critical values, but also determine a quadrilateral region, within which the metallic glass formation is energetically favored. Moreover, the energy differences between the crystalline solid solutions and the disordered states were considered as the driving force for amorphization and were computed by molecular static calculations. The calculation results located an optimized composition area with the driving force much greater than those outside. In addition, the alloys around the composition of Cu(16)Zr(60)Ni(24) were identified to have maximum driving force, and the atomic configurations were also analyzed by the Voronoi tessellation method.
对于 Cu-Zr-Ni 体系，在新提出的名为紧束缚平滑长程二阶矩近似的形式主义下构建了原子间势。应用所构建的势能，进行分子动力学模拟以比较晶态固溶体与无序对应物的相对稳定性。模拟不仅揭示了金属玻璃形成的起源是在溶质浓度超过临界值时晶格格点坍塌，而且确定了一个四边形区域，在该区域内金属玻璃形成在能量上是有利的。此外，将晶态固溶体和无序状态之间的能量差视为非晶化的驱动力，并通过分子静态计算进行计算。计算结果确定了一个优化的组成区域，其驱动力远大于外部的驱动力。此外，通过 Voronoi 剖分方法分析了原子构型，确定了组成大约为 Cu(16)Zr(60)Ni(24)的合金具有最大的驱动力。
