单晶铱取向有关的拉伸变形行为的原子尺度模拟（英文）  

Atomistic Simulation of Orientation-dependent Tension Deformation Behavior of Single Crystal Iridium

作　　者：杨劼人[1] 王虎 胡锐[1] 张璠 李双明[1] 刘毅 罗锡明[2] Yang Jieren;Wang Hu;Hu Rui;Zhang Fan;Li Shuangming;Liu Yi;Luo Ximing(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;Baoji University of Art and Sciences,Baoji 721016,China;Kunming Institute of Precious Metals,Kunming 650106,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]昆明贵金属研究所,云南昆明650106 [3]宝鸡文理学院,陕西宝鸡721016

出　　处：《稀有金属材料与工程》2019年第5期1380-1385,共6页Rare Metal Materials and Engineering

基　　金：National Key Research and Development Program of China(2017YFB0305503);National Natural Science Foundation of China(U1202273)

摘　　要：单晶铱与其它面心立方金属相比表现出反常的变形行为,其本征变形断裂机制仍存在争议。本文进行分子动力学模拟研究了单晶铱在1K下沿[100]、[110]和[111]取向的拉伸变形行为。研究结果表明:单晶铱在3个取向应力-应变曲线上的变形行为差异明显。由于变形机制不同,包括弹性模量、屈服强度、抗拉强度以及延伸率在内的力学性能在几个拉伸取向上或多或少存在差异。在拉伸载荷作用下,[100]取向单晶铱变形主要通过位错滑移还有少量空位聚集;[110]取向的塑性变形由堆垛层错引起;而[111]取向单晶铱断裂前产生的塑性变形量很少。Single crystal iridium exhibits anomalous deformation behaviors in contrast to other fcc-metals and its intrinsic deformation mechanism is still controversial.To investigate the deformation behaviors and underlying deformation mechanisms with respect to crystallographic orientations in single crystal iridium,the molecular dynamics simulations were performed at 1 K to simulate the tensile deformation behavior of bulk single crystal iridium in different loading axis orientations of [100],[110] and [111].Atomic simulation results show that the stress-strain curves differ significantly in three crystallographic orientations.And the mechanical properties including elastic modulus,yield stress,ultimate tensile stress and elongation are more or less different in different crystallographic orientations owing to different deformation mechanisms.Under tensile loading,[100] oriented single crystal iridium deforms predominantly by dislocation slide and partial vacancy coalescence,while plastic deformation in [110] oriented single crystal iridium is initiated by stacking faults.Nevertheless,[111] oriented single crystal iridium undergoes little plastic deformation before breaking.

关 键 词：单晶铱 分子动力学 拉伸变形 晶体取向 

分 类 号：TG146.34[一般工业技术—材料科学与工程]