Nanotwins form in many metallic materials to improve their strength and toughness. In this study, we thoroughly studied the alloying effects of 10 common metal and nonmetal elements on Cu nanotwins by density functional theory (DFT). We calculated the segregation energies to determine if Cu nanotwins attract both the metal and nonmetal alloying elements; these segregation energies were then decomposed to mechanical and chemical components. The Cu-Sn bonds are different from other metal alloying elements, and the strong bond between Cu and the nonmetal element results in the negative values of the chemical contribution. Furthermore, the temperature and concentration have different effects on the nanotwin formation energy of the metal and nonmetal alloying elements. As determined by the Generalized Stacking Fault Energy, Al and nonmetals can inhibit the migration of Cu nanotwin boundary, and the effects of Li, Mg, and Sn are opposite. Our theoretical study serves as the foundation for the engineering nanotwin structures through alloying elements, the elements that may lead to new alloy compositions and thermomechanical processes, and are important complements to the experimental research.

中文翻译：

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合金元素对铜纳米孪晶影响的理论研究

纳米孪晶形成于许多金属材料中，以提高其强度和韧性。在这项研究中，我们通过密度泛函理论（DFT）深入研究了10种常见金属和非金属元素对Cu纳米孪晶的合金化作用。我们计算了偏析能以确定Cu纳米孪晶是否同时吸引了金属和非金属合金元素。这些偏析能然后分解为机械和化学成分。Cu-Sn键与其他金属合金元素不同，Cu和非金属元素之间的强键导致化学贡献为负值。此外，温度和浓度对金属和非金属合金元素的纳米孪晶形成能具有不同的影响。由广义堆叠故障能量确定 Al和非金属可以抑制Cu纳米孪晶边界的迁移，而Li，Mg和Sn的作用相反。我们的理论研究为通过合金元素工程化纳米孪晶结构奠定了基础，这些元素可能导致新的合金成分和热机械过程，并且是对实验研究的重要补充。