Co含量对Ni/Co合金拉伸性能影响的分子动力学分析  

Influence of Co Content on Tensile Properties of Ni/Co Alloys by Molecular Dynamics Analysi

作　　者：周枫林 刘浪 张展展 廖海洋 廖翠姣[1] 曾鑫 ZHOU Fenglin;LIU Lang;ZHANG Zhanzhan;LIAO Haiyang;LIAO Cuijiao;ZENG Xin(School of Mechanical Engineering,Hunan University of Technology,Zhuzhou 412000,China)

机构地区：[1]湖南工业大学机械工程学院,湖南株洲412000

出　　处：《材料科学与工程学报》2023年第6期903-911,共9页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助(项目号11602082,11902113,22072040);湖南省自然科学基金资助(2021JJ30211)。

摘　　要：基于分子动力学方法研究了不同Co含量的Ni/Co的拉伸力学性能。首先,模拟了在100 K、应变率为5×10^(9)/s的条件下,Co含量对Ni/Co拉伸力学性能的影响,其中着重研究了Ni单晶与含Co的体积分数为20%的Ni/Co的微观组织变化趋势。结果表明:相比于单晶Ni,Co原子阻碍了Ni/Co中位错的产生,从而提高了抗拉强度,在缺陷越少的情况下,材料的强度越接近其理论上的强度,Co原子对位错的阻碍作用使得Ni/Co的抗拉强度越接近其理论强度。其次,研究了温度对Ni/Co拉伸力学性能的影响,结果发现Ni/20Co(体积分数为20%,下同)的抗拉强度随着温度的升高呈现下降趋势。这是因为随着温度的升高,原子因剧烈运动导致原子间结合力减弱,fcc结构逐渐转变为other无序原子排列结构,结构越趋于非晶化,从而降低了抗拉强度。最后,研究了应变率对Ni/10Co的拉伸力学性能的影响。结果表明:应变率越大,Ni/10Co抗拉强度越高,高应变率对材料具有强化作用。这是因为高应变率使得位错在材料中的生长和扩展过程受阻,从而达到了强化材料的作用。Based on the molecular dynamics method,the tensile mechanical properties of Ni/Co with different Co contents were studied.The effect of Co content on the tensile mechanical properties of Ni/Co at 100K and strain rate of 5×10^(9)/s was simulated.The microstructure change trend of Ni/Co single crystal and Ni/Co containing 20%volume fraction was studied emphatically.The results show that compared with single crystal Ni,Co atom hinders the generation of dislocation in Ni/Co,it thus improves the tensile strength.In the case of few defects,the strength of the material is close to its theoretical strength,and the blocking effect of Co atoms on the dislocation makes the tensile strength of Ni/Co is close to its theoretical strength.The influence of temperature on the tensile mechanical properties of Ni/Co is also studied.The results show that the tensile strength of Ni/20Co(volume fraction is 20%,the same below)decreases with the increase of temperature.With the increase of temperature,the atoms due to violent movement lead to the weakening of interatomic bonding force,the f.c.c structure transform into a large number of other disordered atomic arrangement structures,thereby reducing the tensile strength.The effect of strain rate on the tensile mechanical properties of Ni/10Co was studied.The results show that the higher the strain rate is,the higher the tensile strength of Ni/10Co is.The higher strain rate has a strengthening effect on the material,because the high strain rate prevents the growth and expansion of the dislocations in the material.

关 键 词：分子动力学 镍基单晶高温合金 镍 钴 

分 类 号：TG146.1[一般工业技术—材料科学与工程]