Pb液滴在Ni基底润湿铺展行为的分子动力学模拟

采用分子动力学方法研究了Pb液滴在Ni(100)晶面、(110)晶面和(111)晶面的铺展润湿行为. 结果表明: Pb液滴在Ni(100)及(111)基底上的润湿铺展现象呈各向同性, 而在Ni(110)基底上的润湿铺展现象呈明显的各向异性, 且这种各向异性源于Ni(110)晶面点阵结构上Pb原子沿不同晶向的扩散机制及速度的明显差异; Pb液滴在Ni(111)晶面上铺展时, 未发生表面合金化, 液滴铺展动力学描述近似满足 R² ∝ t, 而液滴在(100)晶面和(110)晶面上铺展时表面产生合金化现象, 铺展动力学关系近似满足 R⁴ ∝ t, 且液滴在(100)晶面上的铺展速度高于(110)晶面上的铺展速度. 关键词： 分子动力学 润湿各向异性 铺展膜 扩散机制

Molecular dynamics simulation of the wetting behavior of Pb droplet on Ni substrate

Molecular dynamics simulation is performed to investigate the wetting behaviors of Pb droplet on Ni(100), Ni(110) and Ni(111) substrates. It has been shown that the wetting behavior of precursor film is isotropic for Pb droplet on Ni(100) and Ni(111) substrates, but anisotropic for Pb droplet on Ni(110) substrate. The demonstrated anisotropy is attributed to the differences in diffusion mechanism and rate along different crystal orientations for Pb atoms with corresponding anisotropic structure of the crystal lattice on Ni(110) substrate. The spreading dynamics of precursor film on different lattice surfaces are also investigated, which shows that there is no surface alloy formed for Pb droplet on Ni(111) surface and the spreading dynamics can be described by R² ∝ t, but surface alloy forms for Pb droplet on Ni(100) and Ni(110) surface and the spreading dynamics satisfies R⁴∝ t, at the same time the spreading rate of droplet on Ni(100) is higher than that of Ni(110) substrate.
Keywords： molecular dynamics simulation anisotropic wetting behavior precursor film diffusion mechanism