Abstract In recent years, the tungsten-copper composite has attracted much attention due to many excellent performances. In the present work, the wetting behaviors of Cu droplets on W (1 0 0), (1 1 0) and (1 1 1) surfaces had been investigated by molecular dynamics (MD) simulations. Results show that a precursor film with single atomic layer will form on W surfaces. The precursor films showed the anisotropic diffusion due to the difference of diffusion barrios along different directions. Only on the W (1 1 0) surface, the precursor film presents a circle. The precursor film is an oval shape on the W (1 0 0) surface and that is similar to the shape of a triangle on W (1 1 1) surface but the shape of Cu droplet on the W (1 1 1) surface is a circle. The Cu droplet on the W (1 1 1) has the best wettability than others due to the effects of both precursor films and the alloying effect. The Cu droplet on the W (1 1 0) surface has the worst wettability. In addition, the potential of mean force (PMF) analysis was applied to further character the wettability. Besides, the effect of both temperature and substrate structure on wettability was also studied, which shows that the wettability increases with the increased temperature. Moreover, the grooved surface can greatly advance the wetting kinetics along the grooves direction, but in the perpendicular direction, the effect is opposite.

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原子尺度上钨表面铜液滴的润湿特性：分子动力学模拟

摘要 近年来，钨铜复合材料因其优异的性能而备受关注。在目前的工作中，通过分子动力学 (MD) 模拟研究了 Cu 液滴在 W (1 0 0)、(1 1 0) 和 (1 1 1) 表面上的润湿行为。结果表明，在 W 表面将形成具有单原子层的前体膜。由于沿不同方向的扩散壁垒不同，前驱体薄膜表现出各向异性扩散。仅在 W (1 1 0) 表面，前体膜呈现圆形。前驱体薄膜在 W (1 0 0) 面上为椭圆形，类似于 W (1 1 1) 面上的三角形形状，但在 W (1 1 1) 面上的 Cu 液滴形状为一个圆圈。由于前驱体膜和合金化效应的影响，W (1 1 1) 上的 Cu 液滴比其他液滴具有最好的润湿性。W(1 1 0)表面的Cu液滴润湿性最差。此外，应用平均力 (PMF) 分析的潜力来进一步表征润湿性。此外，还研究了温度和基板结构对润湿性的影响，表明润湿性随着温度的升高而增加。此外，凹槽表面可以大大提高沿凹槽方向的润湿动力学，但在垂直方向上，效果相反。还研究了温度和基材结构对润湿性的影响，这表明润湿性随着温度的升高而增加。此外，凹槽表面可以大大提高沿凹槽方向的润湿动力学，但在垂直方向上，效果相反。还研究了温度和基材结构对润湿性的影响，这表明润湿性随着温度的升高而增加。此外，凹槽表面可以大大提高沿凹槽方向的润湿动力学，但在垂直方向上，效果相反。