论文标题
第一原理研究基于Wulff群集模型的纯Al＆Pb融化异常粘度变化机制
First principles study on the mechanism of abnormal viscosity change of pure Al & Pb melts based on Wulff cluster model
论文作者
论文摘要
在本文中，使用WULFF群集模型合并的声子计算用于研究金属熔体（Pb/al）的结构与异常粘度变化之间的关系。尽管表面能的绝对值不会随温度而显着变化，但沃尔夫的形状显然会发生变化。当温度升高到975K时，具有最高相互作用强度的Pb（321）表面完全消失，而异常的粘度下降发生在相同的温度范围内。相反，当温度高于1075K时，相互作用强度最低的Al（100）表面消失，并且在相同的温度范围内，已经观察到异常的粘度上升。异常的粘度下降对应于具有最高相互作用强度（Pb（321）表面）的表面消失，而上升的表面消失对应于最低吸附能（Al（100）表面）的表面消失。所有证据表明，异常粘度变化与沃尔夫形状的变化之间的均匀性不是巧合。异常粘度变化的一种可能机制是，它是由金属熔体中簇的显着结构变化（短距离排序）引起的。
In this paper, the Wulff cluster model combined phonon calculation is used to investigate the relationship between the structure of metallic melts (Pb/Al) and the abnormal viscosity change. Although absolute value of the surface energy does not change significantly with temperature, the Wulff shape changed evidently. When temperature raise to 975K, Pb(321) surface that has the highest interaction strength completely disappears, while the abnormal viscosity drop happens at the same temperature range. Oppositely, Al(100) surface that has the lowest interaction strength disappears when temperature is higher than 1075K, and at the same temperature range, the abnormal viscosity rise has been observed. The abnormal viscosity drop corresponds to the disappearance of surface with the highest interaction strength (Pb(321) surface), while the rise one corresponds to the disappearance of surface with the lowest adsorption energy (Al(100) surface). All evidence indicates that the uniformity between abnormal viscosity change and the change of Wulff shape is not a coincidence. A possible mechanism of the abnormal viscosity change is that it caused by the significant structure change of cluster (short range ordering) in the metallic melts.
