摘要
高熵合金作为一种多主元合金,突破了传统合金单主元的设计思想,体现出不同于传统合金的优异性能,特别在高温、高压、高应变率等极端环境中有着良好的应用前景。从微观、细观与宏观尺度分析高熵合金的冲击变形特性对于其工程应用具有重要的指导作用,主要涉及元素效应、细观结构以及高温高应变率条件对高熵合金冲击损伤演化、微观结构变化和冲击变形演化过程的影响机制。元素效应主要讨论了原子半径差异较大的金属与非金属元素对高熵合金冲击变形行为的影响;根据细观结构不同,将高熵合金分为单相与多相结构,单相高熵合金为塑性较好的面心立方(face centered cubic,FCC)结构、强度较高的体心立方(body centered cubic,BCC)与密排六方(hexagonal closepacked,HCP)结构。多相高熵合金的细观结构为这三种单相结构或者与其他相的组合,多相高熵合金的协同变形能够使其获得更为优异的综合力学性能。高温与高应变率作为外部条件对高熵合金的影响与其他金属相似,高温促进材料软化而高应变率促进材料硬化,部分高熵合金在高温下具有更优异的抗变形能力。针对高熵合金的冲击特性,总结了目前高熵合金在国防工程冲击领域的应用,归纳了高熵合金冲击变形行为研究存在的问题,并进一步对高熵合金在极端条件下的应用进行了展望。
As a kind of multi-principal component alloy,high-entropy alloy breaks through the design idea of traditional single-principal component alloys,and shows excellent properties different from traditional alloy.It has a good application prospect in extreme environments including high temperature,high pressure and high strain rate.Analyzing the impact deformation characteristics of high entropy alloy from micro,meso and macro scale is of great importance for its engineering application,which includes the influences of the element effect,macrostructure and high temperature and high strain rate conditions on the impact damage evolution,microstructure change and impact deformation evolution process of high entropy alloys.In terms of the effect of elements on the mechanical properties of high entropy alloys,the effect of the great difference between the atomic radius of metal and nonmetal elements on the impact deformation is mainly discussed.According to the micro scale structure,the high entropy microstructure of single-phase alloy can be divided into face centered cubic(FCC)structure with better plasticity and body centered cubic(BCC)and hexagonal close-packed(HCP)structure with higher strength.The microstructure of multiphase high entropy alloy is the combination of these three single-phase structures and other phases.The cooperative deformation of multiphase high entropy alloy ensures it to obtain more excellent comprehensive mechanical properties.High temperature and high strain rate as external conditions exhibit similar effect on the high-entropy alloy and other metals.High temperature promotes material softening,while the high strain rate promotes material hardening.Some high entropy alloys have better mechanical properties at high temperature.According to the impact characteristics of high-entropy alloy,the applications of high-entropy alloy in the field of national defense engineering impact are summarized.The existing problems in the research of impact deformation behavior of high-entropy alloy are analyzed,a
作者
陈海华
张先锋
刘闯
林琨富
熊玮
谈梦婷
CHEN Haihua;ZHANG Xianfeng;LIU Chuang;LIN Kunfu;XIONG Wei;TAN Mengting(Department of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,Jiangsu,China)
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
2021年第4期147-170,共24页
Explosion and Shock Waves
基金
国家自然科学基金重大项目(11790292)
国家自然科学基金委员会与中国工程物理研究院联合基金(U1730101)。
关键词
高熵合金
动态力学行为
冲击破坏
损伤演化
微观变形
high-entropy alloy
dynamic mechanical behavior
impact failure
damage evolution
micro-deformation
