The technology of welding heterobimetallic nanowires (NWs) at the nanoscale is of importance for the fabrication of optoelectronic devices. In this work, molecular dynamics simulations are performed to simulate nanojoining of Cu and Al NWs by head-to-head cold-welding as well as tensile properties of obtained welding joints. The results of the climbing image nudged elastic band calculations show that Cu and Al NWs can be successfully connected by cold-welding with high-efficiency and few defects, owing to recrystallization and interfacial diffusion of atoms. Moreover, pressure, temperature, and welding velocity will exert significant influence on tensile properties of joints, including strength and plasticity. The tensile test shows that the fracture usually occurs on the Al NWs rather than the joints of the Cu–Al NW, which demonstrates the high quality of joints. Simulation results obtained in this work will provide atomic scale insights into the cold-welding of heterobimetallic NWs and helpful theoretical guidance for the application of nanojoining.

中文翻译：

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Cu-Al 纳米线的冷焊机理和拉伸行为：分子动力学模拟


纳米级异双金属纳米线 （NW） 焊接技术对于光电器件的制造非常重要。在这项工作中，进行了分子动力学模拟，以模拟通过头对头冷焊对 Cu 和 Al NWs 的纳米连接以及获得的焊接接头的拉伸性能。攀升图像微推松紧带计算结果表明，由于原子的再结晶和界面扩散，Cu 和 Al NWs 可以通过冷焊成功连接，效率高，缺陷少。此外，压力、温度和焊接速度将对接头的拉伸性能产生重大影响，包括强度和塑性。拉伸试验表明，断裂通常发生在 Al NWs 上，而不是 Cu-Al NW 的节理上，这表明节理质量高。本工作获得的仿真结果将为异质双金属 NWs 的冷焊提供原子尺度的见解，并为纳米连接的应用提供有益的理论指导。