纳米Al2O3颗粒对纯Fe液诱导凝固过程的分子动力学模拟

摘要

采用分子动力学(MD)方法模拟了不同半径大小的纳米Al2O3颗粒夹杂在三个温度下(1750、1730和1710K)对纯Fe液的诱导凝固过程,并分析了作为诱导核心的纳米Al2O3颗粒的结构演变及其对Fe原子体系的凝固过程的影响.发现在诱导过程中,纳米Al2O3颗粒的内部保持较好的晶型结构,仅表面原子有结构变形；诱导凝固的Fe原子主要为面心立方(fcc)和密排六方(hcp)原子；纳米Al2O3颗粒的尺寸越大,发生诱导凝固的温度越高；诱导凝固得到的Fe晶体的晶格取向受纳米Al2O3颗粒在Fe液中的漂移程度影响.%The molecular dynamics (MD) method has been used to simulate the solidification process of pure liquid Fe induced by a series of AI2O3 nanoparticles of different radii at three temperatures (1750,1730 and 1710 K). The structural evolution of AIZO3 nanoparticles and the effect of these particles on the solidification process of pure Fe have been analyzed. It was found that during the solidification process, the inner structure of the AI2O3 nanoparticles remained crystalline and structural deformation only occurred in surface atoms. The CTIM-2 method showed that the solidified Fe atoms were mainly faced-centered cubic (fee) and hexagonal closed-packed (hep) atoms. In addition, the temperature at which solidification took place was influenced by the size of the AI2O3 nanoparticles. The orientations of the resulting Fe crystals were influenced by the extent of the drift of the AI2O3 nanoparticles.