预熔二元合金异质固液界面的液膜分离势能  

Disjoining Potential of Premelting Liquid Film in Binary Alloy Heterogeneous Solid-liquid Interface

作　　者：任秀敏 许贤祺 梁洪涛 杨洋[1] REN Xiumin;XU Xianqi;LIANG Hongtao;YANG Yang(Institute of Condensed Matter Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China)

机构地区：[1]华东师范大学物理与电子科学学院凝聚态物理研究所,上海200241

出　　处：《上海金属》2021年第3期94-100,共7页Shanghai Metals

基　　金：国家自然科学基金(No.11504110,11874147);上海市科委科技项目(No.18DZ1112700);中央高校基本科研业务费专项资金、华东师范大学公共创新服务平台(001)。

摘　　要：金属液相界面间的短程相互作用——分离势——是诸多失效过程的关键因素。此热力学参量是晶界基因组工程中的重要组成部分,精确测量分离势对合金微观界面结构与热力学性质的调控具有重要意义。基于预熔铝(100)-铅异质固-液界面体系为研究对象的分子动力学模拟,测量了6种不同温度固相铝-预熔铝膜和预熔铝膜-液相铅界面位置的涨落概率密度分布及预熔铝膜厚度涨落概率密度分布,并应用Fensin等提出的分离势计算方法获得了该体系的单指数衰减的分离势。计算结果与唯象理论估测的分离势结果相符。此外,还讨论了双指数函数描述预熔异质固-液界面分离势在理论上的可能性,推断双指数叠加形式的分离势与两个不同界面密度波衰减长度有关。Short range interaction between liquid metal interfaces,that is to say,disjoining potential,is the key factor in many failure processes.This thermodynamic parameter is an important component of grain boundary genomic engineering.It is of great significance to accurately calculate the disjoining potential for the regulation of the microstructure and thermodynamic properties of the alloy.Based on the molecular dynamics simulation of the heterogeneous solid-liquid interface system of premelting Al(100)-Pb,the fluctuation probability density distribution of the position of Al(solid)-Al(premelting)interface and Al(premelting)-Pb(liquid)interface at six different temperatures,as well as the probability density distribution of the thickness of premelting Al film were measured.The disjoining potential of single exponential decay in this system was obtained by using the method proposed by Fensin et al.The results were in good agreement with those estimated by the phenomenological theory.In addition,the theoretical possibility of the double exponential function to describe the disjoining potential of the premelting heterogeneous solid-liquid interface was discussed.It was inferred that the disjoining potential in the form of double exponential superposition was related to the attenuation length of two different interface density waves.

关 键 词：异质合金 固-液界面 预熔化相变 分离势 分子动力学 

分 类 号：O41[理学—理论物理]