利用分子动力学模拟的方法，采用嵌入原子势能模型，研究不同尺寸的纳米Au颗粒的熔化及烧结过程。结果表明，纳米金颗粒的熔点低于其块体材料的熔点，熔化过程从表面向内部进行。根据烧结颈的长大曲线确定不同尺寸的纳米Au颗粒的起始烧结温度，颗粒的最佳烧结温度范围为起始烧结温度至纳米颗粒完全熔化的温度，且升温过程中颗粒的表面熔化温度和熔点等特征温度与N-1/3成线性关系(N为Au纳米颗粒的原子数)。纳米颗粒烧结过程中原子的迁移和烧结颈长大主要有表面扩散、晶界扩散或粘性流动等机制。%The melting and sintering processes of different-sized gold nanoparticles were investigated using molecular dynamics simulation within the framework of the embedded atom method (EAM). It is found that the melting point of nanoparticles is lower than that of bulk. The melting process begins from the surface to the interior part. The onset sintering temperature can be decided by the sintering neck width growth curve, and the optimum sintering temperature range for Au nanoparticles is from the onset sintering temperature to the melting temperature. It is also found that the temperature of surface melting point and melt point for different-sized particles are linearly related to the atoms number N-1/3. The major atomic migration and sintering neck growth mechanisms are grain-boundary diffusion, surface diffusion or viscous flow.
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