高熵合金强韧化的研究进展  

Research Progress on Strengthening and Ductilizing High-Entropy Alloys

作　　者：谭雅琴 王晓明[2] 朱胜[2] 乔珺威[1] TAN Yaqin;WANG Xiaoming;ZHU Sheng;QIAO Junwei(Research Center for High-entropy Alloys,School of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;National Key Laboratory for Remanufacturing,Academy of Armored Forces Engineering,Beijing 100072,China)

机构地区：[1]太原理工大学材料科学与工程学院,高熵合金研究中心,太原030024 [2]装甲兵工程学院装备再制造技术国防科技重点实验室,北京100072

出　　处：《材料导报》2020年第5期120-126,共7页Materials Reports

基　　金：装甲兵工程学院装备再制造技术国防科技重点实验室资助(61420050204);北京科技大学新金属材料国家重点实验室开放课题资助(2016-ZD03)~~

摘　　要：高熵合金拥有优异的力学性能,包括高强度、高硬度、良好的耐蚀性和耐磨性等,作为结构材料应用极具潜力。对高熵合金力学性能优化的研究尽管仍处于探索阶段,但已经引起了广泛关注并取得了一些成果。传统上合金的强化机制可分为固溶强化、位错强化、细晶强化和第二相强化。考虑到高熵合金倾向于形成固溶体,固溶强化是一种行之有效的强化机制。可通过加入其中一种主元或者与主元半径差不多的元素形成置换固溶体(通常是过渡金属元素);也可以加入小半径元素如C、N、B等形成间隙固溶体。热机械处理是金属材料常见的预处理工艺,通过轧制等压力加工手段和再结晶退火能够很明显地提高位错密度以及细化晶粒尺寸,从而实现高熵合金的强韧化。第二相强化是近年来比较流行的强化方式。热力学分析可以有效帮助确定退火温度以获得第二相颗粒,甚至控制第二相的尺寸和形貌。位错与第二相颗粒以切过机制或绕过机制发生交互作用,从而提高合金的力学性能。除通过改变内部组织来提升性能外,通过表面处理也可实现强韧化。对塑性较好的高熵合金进行渗碳、渗氮和镀膜等处理通常可以获得表硬内韧的组织结构。渗碳渗氮对表层的硬化源于间隙固溶和第二相析出,镀膜的优化效果则源于膜与基体的紧密结合,可以同时表现出两者的性能优势。本文主要从内在强化机理的角度出发,论述了添加组元、热处理工艺等对高熵合金的强韧化效果。此外,还介绍了几种典型的表面处理对高熵合金强韧化的影响。High-entropy alloys(HEAs)have displayed promising application potential as structural materials owing to their excellent mechanical properties,such as high strength,high hardness,good corrosion and wear resistance.The research upon mechanical properties optimization for HEAs has provoked considerable attention and some preliminary achievements have been made.Traditionally,the strengthening mechanisms of alloys can be classified as solid-solution strengthening,dislocation hardening,grain-boundary strengthening and secondary-phase hardening.Because HEAs have high tendency to form solid solution,solid-solution strengthening is consi-dered as a major and effective way for HEAs.In this regard,we can use one of the principal elements or an element similar to other principal elements to generate substitution solid solution.Or we can add some atoms with small radius,such as C,N,and B,so the lattice distortions can be obtained.Thermo-mechanical techniques,as commonly used prior treatment method,are also applicable for HEAs,in which cold-rolling,for-ging,recrystallization annealing,etc.all can significantly increase dislocation density and refine grains.In addition,there is a more prevailing way in recent years-secondary-phase hardening.We can easily determine the annealing temperature by thermodynamic analysis to obtain secondary phase particles,and even to control their size and morphology.Thus HEAs mechanical properties can be improved due to the interaction between dislocations and secondary phase particles,with either shearing mechanism or Orowan-bypassing mechanism.Apart from changing internal structure,surface treatment is also helpful in strengthening and ductilization.For HEAs with fine plasticity,carburizing&nitriding and coating generally facilitate to obtaining the structure with hard surface and ductile interior.The hardening effect of carburizing&nitriding stems from interstitial solid solution and secondary phase precipitation,while the role of coating process depends on the strong adhesion between coating a

关 键 词：高熵合金 力学性能 强韧化 固溶强化 位错强化 细晶强化 第二相强化 表面强化 热机械处理 渗碳 渗氮 镀膜 

分 类 号：TG135[一般工业技术—材料科学与工程]