摘要
对纳米晶(单晶、多晶)CoNiCrFeMn高熵合金的力学性能评估有助于理解高熵合金材料物性,更好地服务于核反应堆包壳管、航空发动机、喷气涡轮叶片等国防应用领域发展.本文提出对纳米晶CoNiCrFeMn高熵合金微结构演化与力学性能间的相关性展开研究.基于纳米压痕法,研究了纳米晶高熵合金和纳米晶镍的变形行为与力学性能,比较了使役温度对纳米晶CoNiCrFeMn高熵合金和纳米晶Ni的力学性能与微结构演化差异.结果表明:单晶高熵合金力学性能(最大承载荷、硬度、杨氏模量、接触刚度)优越于单晶镍主要源于单晶高熵合金外形呈鼓包式结构内的位错滑移与拓展传播受到局限域的阻滞作用.极端低温5 K下的材料力学性能表现最佳,多晶Ni相比单晶Ni的最大承载荷、硬度、杨氏模量、接触刚度降幅分别达28.9%,20.27%,32.61%,36.4%;多晶CoNiCrFeMn高熵合金相比单晶CoNiCrFeMn高熵合金的最大承载荷、硬度、杨氏模量、接触刚度降幅依次达21.74%,23.61%,23.79%,22.90%.此外,多晶高熵合金力学性能相比单晶高熵合金对温度敏感性更强,其力学性能随温度升高近似线性下降.对多晶高熵合金和多晶镍而言,晶界不仅是位错滋生、拓展、繁衍的起源区,更是萌生缺陷、产生裂纹拓展与失效的集中域.受应力驱动晶界边缘的微结构演化和缺陷存在,多晶材料力学性能弱于单晶材料.
Physical property and material mechanical performance of nano crystalline(single crystal,polycrystalline)CoNiCrFeMn alloy can be known well through an in-depth understanding of the micro-evaluation behaviour of micro dislocation,so that it can better be used in defense fields,such as nuclear reactor cladding tubes,aircraft engines,jet turbine blades and others.In this paper we propose to study the correlation between microstructure evolution and mechanical properties for nanocrystalline CoNiCrFeMn high entropy alloy.The force driven material deformation behaviors and mechanical properties of nano crystalline alloy and Ni material are studied by using the nanoindentation method,and effects of temperature on the mechanical properties and micro-structure evolution are compared as well.Research results show that the mechanical properties(maximum load,hardness,Young’s modulus and contact stiffness) of single crystal alloy are superior to those of single crystal Ni,which mainly stems from the fact that the single crystal high entropy alloy with a drum-shape structure is produced under loa.ding period,and the slip and expansion of dislocations in the bulge structure are blocked.At a low temperature(5 K),the maximum load,hardness,Young’s modulus and contact stiffness of poly crystalline Ni decrease by 28.9%,20.27%,32.61% and 36.4% respectively in comparison with those of single crystal Ni.The maximum load,hardness,Young’s modulus and contact stiffness of poly crystalline CoNiCrFeMn material decrease by 21.74%,23.61%,23.79% and 22.90% respectively with respect to those of single CoNiCrFeMn high entropy alloy.In addition,the mechanical properties of poly crystalline alloy are more sensitive to temperature than those of single crystal high entropy alloy,whose mechanical properties decrease approximately linearly with temperature increasing.For polycrystalline CoNiCrFeMn and Ni material,the grain boundary is not merely the origin region of dislocation breeding,expansion and reproduction,but also the concentration region of defect initiation,crack expansion and failure.Its mechanical properties are weaker than those of single crystal materials due to micro-structure evolution of grain boundaries driven from stress concentration and defects existence.
作者
陈晶晶
邱小林
李柯
周丹
袁军军
Chen Jing-Jing;Qiu Xiao-Lin;Li Ke;Zhou Dan;Yuan Jun-Jun(School of Mechanical and Eelectrical Engineering,Nanchang Institute of Technology,Nanchang 330044,China;College of Electrical and Mechanical Engineering,Key Laboratory of Optoelectronic Material in Jiangxi,Nanchang 330044,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第19期363-374,共12页
Acta Physica Sinica
基金
南昌理工学院机械表/界面摩擦磨损与防护润滑校级研究中心、江西省教育厅科学技术研究项目(批准号:GJJ212101,GJJ219310)
南昌市重点实验室建设项目(批准号:2020-NCZDSY-005)资助的课题。
关键词
CoNiCrFeMn高熵合金
纳米压痕
温度响应
力学性能
分子模拟
CoNiCrFeMn high entropy alloy
nano indentation
temperature response
mechanical performance
molecular simulation
作者简介
通信作者:陈晶晶.E-mail:chenjingjingfzu@126.com。
