原子模拟研究铍〈1120〉对称倾侧晶界的能量与结构特性  

Energetic and Structure Characteristics of the〈1120〉Symmetric Tilt Grain Boundaries of Beryllium:Insight from Atomic Simulations

作　　者：王慧明 金剑锋 王东新 许德美 郭凯琪 杨培军 秦高梧 WANG Huiming;JIN Jianfeng;WANG Dongxin;XU Demei;GUO Kaiqi;YANG Peijun;QIN Gaowu(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;State Key Laboratory of Special Rare Metal Materials,Northwest Rare Metal Materials Research,Institute Ningxia Co.,Ltd.,Shizuishan 753000,Ningxia,China;School of Materials Science and Engineering,North Minzu University,Yinchuan 750030,China)

机构地区：[1]东北大学材料科学与工程学院,沈阳110819 [2]西北稀有金属材料研究院宁夏有限公司,稀有金属特种材料国家重点实验室,宁夏石嘴山753000 [3]北方民族大学材料科学与工程学院,银川750030

出　　处：《材料导报》2025年第4期179-185,共7页Materials Reports

基　　金：西北稀有金属材料研究院宁夏有限公司稀有金属特种材料国家重点实验室开放课题基金(SKL2018K003)。

摘　　要：铍(Be)具有优异的物理、力学等性能,在航空航天、国防、核工业等关键领域发挥了非常重要的作用。但金属铍(αBe)是密排六方结构晶体,其结构的各向异性对力学性能会产生显著的影响,限制了铍的应用。本研究首先构建出〈1120〉对称倾侧晶界(STGB)的原子模型,通过分子动力学方法模拟计算出不同倾侧角(2θ)的晶界能(ESTGB),并分析几种典型界面的原子结构,从而探索铍中倾侧晶界随θ角度变化的各向异性特点。研究发现:当θ在0~90°内变化时,根据晶界能的变化规律,可将θ划分为六个区域。对于小角度晶界区(0°<θ≤15°),晶界能随θ的增加而增大。而对于大角度晶界(θ>15°),结果显示(1013)、(1012)、(1011)孪晶及(2021)倾侧晶界对应的ESTGB较低;晶界能最低点对应(1013)孪晶(θ=31.11°),其值为289 mJ/m^(2),其次是(1011)孪晶(θ=61.09°),为336 mJ/m^(2),然后是(1012)孪晶(θ=42.15°),为536 mJ/m^(2),最后是(2021)倾侧晶界(θ=74.56°),为582 mJ/m^(2)。进一步分析界面原子结构发现,三种孪晶平面和(2021)晶界平面的原子结构和能量均呈周期性排布;当θ在这四个角度附近小幅变化时,界面的特征变化显著。最后,对比密排六方结构金属铍、镁、钛的〈1120〉对称倾侧晶界能量的模拟结果,发现其晶界能随θ变化的趋势相似,但铍对应的晶界能明显高于钛和镁。上述结果可为高效地开发铍及其合金提供理论参考和设计思路。Beryllium(Be)has many exceptional physical and mechanical properties and plays an irreplaceable key role in some special fields,such as aerospace,national defense and nuclear industries.However,the mechanical properties ofα-Be are significantly affected by the anisotropic characteristic of its hexagonal close-packed(HCP)lattice structure,which limits its applications.In this study,molecular dynamics(MD)simulations are used to investigate the energetic and structure characteristics of the〈1120〉symmetrical tilt grain boundary(STGB)inα-Be,in which the GB energy with the tilt angle(2θ)is calculated and the atomic structure at the interface is analyzed,and the anisotropy of the tilting grain boundary with theθis examined.It is found that theθcan be divided into six regions based on the variation of the GB energy when it ranges from 0°to 90°.For low-angle STGBs(0°<θ≤15°),the GB energy increases with theθ.However,for high-angle STGBs(θ>15°),the results demonstrate that the(1013),(1012),(1011)twin boundaries,and the(2021)tilt grain boundary correspond to the lower ESTGB.The(1013)twin boundary(θ=31.11°)exhibits the lowest GB energy with the ESTGB of 289 mJ/m^(2),followed by the(1011)twin boundary(θ=61.09°)with the ESTGB of 336 mJ/m^(2),the(1012)twin boundary(θ=42.15°)with the ESTGB of 536mJ/m^(2),and finally the(2021)tilt boundary(θ=74.56°)with the ESTGB of 582 mJ/m^(2).Further analysis of the atomic structure of these boundaries reveals that the atomic structures and energies of the three twin and(2021)GB planes exhibit periodic arrangements.Slight changes inθnear these angles significantly alter the characteristics of the corresponding interface.Finally,when comparing the GB energy at the same〈1120〉STGBs of HCP-Be,Mg and Ti,it is found that the trend of GB energy variation with theθis similar.However,the ESTGB of Be is greater than that of Mg and Ti.These findings can provide guidance to design and develop beryllium and its alloys in an efficient way.

关 键 词：金属铍 分子动力学 对称倾侧晶界 晶界能 各向异性 

分 类 号：TB31[一般工业技术—材料科学与工程]