纳米级不互溶体系中的界面及三叉线演化

发布时间：2018-06-03 18:31

本文选题：纳米多层膜 + 纳米薄膜　；参考：《上海交通大学》2015年硕士论文

【摘要】：纳米级不互溶体系的界面及三叉线在高温下会发生迁移,受此作用影响的纳米多层膜的热稳定性问题和纳米薄膜中的晶粒缩小加速问题受到研究者们的关注。我们主要使用计算模拟的方法,研究了界面能各向异性对纳米多层膜热稳定性的影响,以及三叉线的迁移率、线张力对纳米薄膜中晶界迁移的影响。界面能各向异性条件下平直初始界面演化形成折线界面,这种起伏的界面使界面总能量最低,界面的起伏周期可以通过尖角处具有位错能量和尖角形成能的模型进行估算,以上结果与实验结果符合得较好。在晶界热沟槽主导的纳米多层膜热稳定性问题中,我们提出了判断界面能各向异性条件是促进还是阻碍晶界沟槽加深的方法。在纳米薄膜中的圆柱形晶粒缩小过程中,较低的三叉线迁移率会使膜层在沟槽处脱离的可能性增大,而三叉线线张力是造成晶粒缩小最后阶段加速的重要原因。我们发现的晶界运动速度与三叉线迁移率的函数关系有助于通过实验得到三叉线迁移率。
[Abstract]:The interfacial and trigeminal lines of nanoscale immiscible systems migrate at high temperature. The thermal stability of nanomultilayer films and the acceleration of grain shrinkage in nanocrystalline films are concerned by researchers. The influence of interfacial energy anisotropy on the thermal stability of nanocrystalline multilayer films and the effects of triangulation line mobility and wire tension on grain boundary migration in nanocrystalline films were studied by means of computational simulation. Under the condition of anisotropic interface energy, the flat initial interface evolves to form a broken line interface, which makes the total energy of the interface the lowest. The fluctuation period of the interface can be estimated by the model with dislocation energy and angular formation energy at the sharp corner. The above results are in good agreement with the experimental results. In the thermal stability of nanocrystalline multilayer films dominated by grain boundary thermal grooves, a method is proposed to determine whether the interface energy anisotropy conditions promote or hinder the deepening of grain boundary grooves. During the reduction of cylindrical grains in nanocrystalline films, the lower triangulation mobility increases the possibility of the film leaving at the grooves, and the tension of the tri-lines is the important reason for accelerating the final stage of grain reduction. The relationship between the velocity of grain boundary motion and the mobility of triple-line is found to be helpful to obtain triple-line mobility through experiments.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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