摘要
随着对高熵合金的深入研究,通过实验建立高熵合金主要元素对合金性能的影响规律与机制,工作量较大并存在较大的不确定性,基于密度泛函理论的第一性原理计算可以很好地解决这类问题。通过计算,可以从原子、分子层面来讨论材料的显微结构和性能。采用基于平面波赝势的CASTEP的方法对CoCuxFeNi(x=0.5,1.0,1.5)高熵合金以及CoxCuFeNi(x=0.5,1.0,1.5)高熵合金进行第一性原理计算,并对晶体结构以及力学性能进行了研究。结果表明,随Cu含量的增加,晶格常数增大,密度不断减小,结合能不断降低,CoCu0.5FeNi的体积模量K、剪切模量G、弹性模量E以及硬度均高于其它Cu含量的CoCuxFeNi高熵合金,但热力学稳定性较差;随Co含量的增加,晶格常数减小,密度不断增大,结合能不断升高,Co1.5CuFeNi的体积模量K、剪切模量G、弹性模量E以及硬度均高于其它Co含量的CoxCuFeNi高熵合金,但其结合能较高,在热力学条件下的稳定性较差。
With the in-depth study of HEAs,the rule and mechanism of the influence of the main elements of HEAs on the properties of HEAs established by experiments have a large amount of work and great uncertainty.But it can be solved through first principle calculation based on density universal funcition theory.The microstructure and properties of materials can be discussed in terms of atoms and molecules.Therefore,the CASTEP method based on plane wave pseudopotentiality was adopted to calculate CoCuxFeNi(x=0.5,1.0,1.5)HEAs and CoCuxFeNi(x=0.5,1.0,1.5)HEAs by first principle in this study,and the crystal structure and mechanical properties were studied.The results show that with the increase of Cu content,the lattice constant increasedbut the density and the binding energy decreased.The volume modulus K,shear modulus G,elastic modulus E and the hardness of CoCu0.5FeNi HEAs were higher than that of other CoCuXFeNi HEAs,but the thermodynamic stability was poor.However,with the increase of Co content,the lattice constant decreased,but the density increased and the binding energy increasedcontinuously.The volume modulus K,shear modulus G,elastic modulus E and the hardness of Co1.5CuFeNi HEAs with higher Co content were all higher than that of other CoCuFeNi HEAs.But their binding energy was higher and stability was poor under thermodynamic conditions.
作者
王根
李新梅
WANG Gen;LI Xinmei(College of Mechanical Engineering, Xinjiang University, Urumchi 830047, China)
出处
《功能材料》
EI
CAS
CSCD
北大核心
2020年第3期3189-3195,共7页
Journal of Functional Materials
基金
国家自然科学基金资助项目(51865055,51561029)
关键词
高熵合金
第一性原理计算
平面波赝势
晶体结构
力学性能
HEAs
the first principle calculation
plane wave pseudopotential
crystal structure
mechanical properties
