温度对金纳米线拉伸塑性变形影响的分子动力学模拟研究  

Molecular dynamics simulation of the effect of temperature on the tensile plastic deformation of Au nanowires

作　　者：廉会彬 王占鑫 翟亚迪[1] 王立华[1] 韩晓东[1,2] LIAN Huibin;WANG Zhanxin;ZHAI Yadi;WANG Lihua;HAN Xiaodong(Beijing Key Laboratory of Advanced Materials Microstructure and Properties,Institute of Microstructure and Properties of Advanced Materials,Beijing University of Technology,Beijing 100124;Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen Guangdong 518000,China)

机构地区：[1]北京工业大学固体微结构与性能研究所,北京市先进材料微结构与性能重点实验室,北京100124 [2]南方科技大学材料科学与工程系,广东深圳518000

出　　处：《电子显微学报》2024年第4期447-453,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.12174014).

摘　　要：小尺寸金(Au)纳米线因具有优异的力学性能而受到广泛关注。而之前的相关研究大多是在常温下进行,不同低温下的研究较少。研究金纳米线在低温下塑性变形行为,能够为其低温下的应用提供理论依据。本文采用分子动力学模拟的方法,研究了不同温度下菱形Au纳米线的力学行为,发现Au纳米线的强度和塑性变形能力会随温度降低而增大。另外,Au纳米线的塑性变形机制受温度影响会发生转变。在175~350 K时,其塑性变形机制主要为Shockley偏位错发射导致纳米线形成大量层错,之后出现切变和过早颈缩。在50~140 K时则转变为以偏位错发射为主,首先形成平滑的孪晶界并发生迁移,之后形成交叉的孪晶界并继续迁移,过程中生成大量孪晶,最终产生40.16%的均匀变形。Small⁃sized gold(Au)nanowires have garnered significant attention due to their excellent mechanical properties.However,most previous studies have focused on room temperature,with limited research exploring their behavior at low temperatures.Investigating the plastic deformation behavior of gold nanowires at low temperatures can provide a theoretical foundation for their applications in such environments.In this paper,molecular dynamics simulations were employed to examine the mechanical behavior of rhombic Au nanowires across different temperatures.The study revealed that the strength and plastic deformation capability of Au nanowires increased as the temperature decreased.Moreover,the plastic deformation mechanism of Au nanowires underwent a temperature⁃dependent transition.In the temperature range of 175 K to 350 K,the plastic deformation mechanism was primarily governed by the emission of Shockley partial dislocation,which led to the generation of numerous stacking fault within the nanowires,followed by shear and premature necking.At lower temperatures,ranging from 50 K to 140 K,the mechanism shifted to partial dislocation emission,initially forming smooth twin boundaries and undergoing migration.This was followed by the formation of intersecting twin boundaries,which continued to migration.This process generated a substantial amount of twinning and result ed in superplastic deformation of up to 40.16%.

关 键 词：分子动力学模拟 金纳米线 塑性变形 孪晶 面心立方金属 

分 类 号：TG146[一般工业技术—材料科学与工程] O77[金属学及工艺—金属材料] O733[金属学及工艺—金属学] O763[理学—晶体学] TG115.215.3