摘要
采用第一性原理计算方法研究了不同Sc元素含量对新型TiZrHfNbSc_(x)难熔高熵合金的相结构、弹性常数和弹性性能的影响,该方法基于平面波赝势和密度泛函理论,采用虚拟晶体近似法建立固溶体结构模型。通过计算原子尺寸差异(δ)、价电子浓度(VEC)、原子分布情况(λ)等条件可知TiZrHfNbSc_(x)难熔高熵合金主要以单一的体心立方(bcc)无序固溶体结构为主。第一性原理计算结果表明,合金完全以金属键结合,具有良好的内在塑性,Sc元素的加入提高了TiZrHfNbSc_(x)高熵合金的结构不稳定性,合金结构更倾向于形成面心或密排六方的晶体结构;而且随着Sc元素含量的增加,TiZrHfNbSc_(x)难熔高熵合金的晶格常数逐渐增加,合金密度、杨氏模量(E)、体弹性模量(B)、剪切弹性模量(G)等降低,体弹模量和剪切模量的比值(B/G)、泊松比(ν)则呈现增加的趋势。因而随着Sc元素含量增加,合金的硬度降低,抗体积、剪切变形的能力减弱,合金的韧性逐渐增强,塑性变形能力提高。
With the development of modern industrial technology,the development of new materials to meet the application requirements of harsh environment has become one of the important topics studied by scientists all over the world.Due to the effects of high entropy,slow diffusion,lattice distortion,cocktail and microstructure stability,high entropy alloys have outstanding characteristics,such as high strength,high hardness,good wear resistance,good corrosion resistance,high thermal resistance,high conductivity and excellent high temperature oxidation resistance.Therefore,the high entropy alloys have broad application prospects in the fields of aerospace,marine engineering,new energy and nuclear energy,which are considered to be the most promising new alloy system in the 21st century,and have become a research hotspot in the field of materials at home and abroad.At present,high entropy alloy systems are mainly divided into two categories:the first is alloy systems dominated by Al and IV periodic elements Fe,Co,Ni,Cr,Cu and Mn;the second type is refractory high entropy alloy system dominated by refractory metals Ti,Zr,HF,W,Mo,Ta,Nb and V.The preparation methods of refractory high entropy alloys are complex and the component content is not easy to control.At present,the research progress on the microstructure,microstructure and properties of refractory high entropy alloys is slow.Based on the first principal calculation method of density functional theory,the relationship between microstructure and properties of materials can be discussed from the molecular and atomic levels.Moreover,the mechanism of the effect of each component element on the structure and properties of high entropy alloys can be further explored.The effects of different Sc content on the phase structure,elastic constants and elastic properties of TiZrHfNbSc_(x) (x=0,0.1,0.4,0.7,1.0;mole fraction)refractory high entropy alloy were studied by first principal calculation method.Based on the plane wave pseudopotential and density functional theory,the struct
作者
江洪林
胡志方
宋春燕
贵永亮
尹延西
Jiang Honglin;Hu Zhifang;Song Chunyan;Gui Yongliang;Yin Yanxi(GRINM Resources and Environment Tech.Co.,Ltd.,Beijing 101047,China;Beijing Engineering Research Center of Strategic Nonferrous Metals Green Manufacturing Technology,Beijing 101047,China;College of Metallurgy&Energy,North China University of Science and Technology,Tangshan 063000,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2022年第10期1383-1389,共7页
Chinese Journal of Rare Metals
基金
国家科技部中俄国际合作专项项目(2010DFR50800)资助
关键词
高熵合金
第一性原理
晶体结构
弹性性能
high entropy alloys
first principle
crystal structure
elastic propertys
