B2-NiAl纳米薄膜厚度对其弹性性能影响的模拟研究  

Simulation studies on the influence of nanofilm thickness on the elastic properties of B2-NiAl

作　　者：阳喜元[1,2] 张晋平[2] 吴玉蓉[3] 刘福生[4] 

机构地区：[1]岭南师范学院物理科学与技术学院,湛江524048 [2]湖南文理学院物理与电子科学学院,常德415000 [3]厦门理工学院材料科学与工程系,厦门361024 [4]湖南工业大学材料与冶金工程学院,株洲412007

出　　处：《物理学报》2015年第1期254-262,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51201063);湖南文理学院科研项目(批准号:13ZD11;13YB31)资助的课题~~

摘　　要：本文应用分子动力学(MD)技术和改进分析型嵌入原子模型(MAEAM)研究B2-Ni Al纳米薄膜有关弹性性能的尺寸效应和表面效应.首先计算块体B2-Ni Al合金的弹性性能和该类薄膜的厚度尺寸对其表面能的影响,发现块体B2-Ni Al薄膜的弹性性能与已有的实验和理论计算结果接近,而薄膜表面能仅与表面原子组分有关,基本不受其厚度尺寸的影响.在此基础上,重点研究了纳米薄膜的弹性性能随其厚度尺寸变化关系,发现所有纳米薄膜弹性性能都随其尺寸增加而呈指数变化,并受表面原子组分调控.并进一步分析尺寸影响纳米薄膜弹性性能的内在机理,发现纳米薄膜的晶面间距偏离和表面是影响其弹性性能随尺寸变化的主要因素,并与以前实验和理论研究结果相符合.In this paper the molecular dynamics （MD） technique and the modified analytic embedded atom method （MAEAM） are applied to study the influence of size and surface condition of the nanofilm on the elastic properties of B2-NiAl, The elastic properties of the bulk NiA1 alloy and the size dependence of the surface energy of nanofilms are first calculated. It is found that the calculated results of the elastic properties are consistent with those from experiments and theories; and the surface energy, which is barely influenced by the thickness, is controlled by the surface atomic composition. On this basis, our investigations are mainly focused on the relationship between the elastic properties of nanofilms and their thickness. The obtained results indicate that the elastic properties of the nanofilm may change exponentially with the increasing thickness , which can also be regulated by the surface atomic composition. Furthermore, the inherent mechanism of the thicknes and surface that affects this relationship is analyzed in detail, showing that the surface atomic composition and the deviation of interplanar spacing in nanofims are two major factors for determining the thickness dependence of the elastic properties. These are in good agreement with the previous theoretical and experimental studies.

关 键 词：厚度 弹性性能 B2-NiAl纳米薄膜 模拟研究 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TB383.2