论文部分内容阅读
本文使用分子动力学方法对金属钨的熔化过程进行了数值模拟,分析了钨在熔化过程中的结构、系统内能变化以及表面熔化过程固-液界面变化情况,初步分析了表面熔化现象的机理。模拟过程采用嵌入原子模型(EAM)描述原子间相互作用,模拟结果表明,嵌入原子模型适合于计算固-液相变过程,表面熔化过程是由表面处最外层原子的不稳定性触发的。对于均匀熔化过程,晶体在4700 K下发生固-液相变;对于表面熔化过程,计算获得了不同温度(3800～4800 K)下的熔化速度,拟合出熔化速度公式,得到的表面熔化热力学熔点与已有实验结果基本符合。
In this paper, molecular dynamics simulation is used to simulate the melting process of tungsten metal. The structure, internal energy and the solid-liquid interface change of tungsten during melting are analyzed. The mechanism of surface melting is analyzed preliminarily . The simulation describes the interaction between atoms using an embedded atomic model (EAM). The simulation results show that the embedded atomic model is suitable for the calculation of solid-liquid phase transitions. The surface melting process is triggered by the instability of the outermost atoms on the surface. For the uniform melting process, the crystal undergoes solid-liquid phase transformation at 4700 K. For the surface melting process, the melting speed at different temperatures (3800 ~ 4800 K) is calculated and the melting rate formula is fitted to obtain the surface melting thermodynamics Melting point and the experimental results are basically in line.