激光与光电子学进展, 2019, 56 (2): 021603, 网络出版: 2019-08-01
金属Ag固化过程中的空位形成研究 下载: 839次
Vacancy Formation During Solidification of Metal Ag
材料 缺陷俘获 空位 固液界面 界面温度 生长机制 materials defect trapping vacancy solid-liquid interface interfacial temperature growth mechanism
摘要
采用分子动力学方法,研究了金属Ag固液界面在固化过程中的动力学过程及缺陷俘获。结果发现,金属Ag的界面温度存在某个特征值(T *),生长速度在这个特征温度附近达到最大值。同时发现液体在产生晶体时缺陷以空位为主。计算结果表明,缺陷浓度与界面温度之间存在线性关系,缺陷浓度随着界面温度的降低而逐渐增大,在特征温度附近发生转变。同时发现缺陷浓度与生长速度相关,当界面温度高于特征温度(T>T *)时,二者存在近似线性关系且与方向无关,但当界面温度低于特征温度(T<T *)时,(100)方向和(110)方向存在着明显的各向异性,表明缺陷俘获与生长机制转变有关。
Abstract
The kinetics and defect trapping at the solid-liquid interface of simple metal Ag during the solidification process are investigated by molecular dynamics simulation. It is found that there exists a certain characteristic value (T*) for the interfacial temperature of metal Ag at which the growth rate reaches a maximum value. Meanwhile, the vacancy defects are predominant in the solidification process of liquids. The calculation results show that there exists a linear relationship between defect concentration and interfacial temperature. The defect concentration gradually increases with the decrease of interfacial temperature, and a transition occurs near this characteristic temperature. In addition, the defect concentration is found to be dependent on growth velocity. Above the characteristic temperature (T>T*), the defect concentration almost linearly depends on the growth velocity, and both are independent on orientations. In contrast, below the characteristic temperature (T
张海燕, 汪丽春. 金属Ag固化过程中的空位形成研究[J]. 激光与光电子学进展, 2019, 56(2): 021603. Haiyan Zhang, Lichun Wang. Vacancy Formation During Solidification of Metal Ag[J]. Laser & Optoelectronics Progress, 2019, 56(2): 021603.