Cantor合金力学性能及其组织稳定性研究进展  

Research Development of Mechanical Properties and Microstructure Stability of Cantor Alloys

作　　者：庞宝林 王曼[1,2] 席晓丽[1,3] PANG Baolin;WANG Man;XI Xiaoli(Key Laboratory of Advanced Functional Materials,Ministry of Education,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China;National Engineering Laboratory for Industrial Big-data Application Technology,Beijing University of Technology,Beijing 100124,China;Collaborative Innovation Center of Capital Resource-recycling Material Technology,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学材料与制造学部新型功能材料教育部重点实验室,北京100124 [2]北京工业大学工业大数据应用技术国家工程实验室,北京100124 [3]北京工业大学首都资源循环材料技术省部共建协同创新中心,北京100124

出　　处：《材料导报》2022年第2期179-183,共5页Materials Reports

基　　金：国家自然科学基金-青年项目(51901005);国家重点研发计划课题(2018YFC1901705)。

摘　　要：Cantor合金是由英国的Cantor教授于2004年首次提出,是指由Co、Cr、Fe、Mn、Ni五种元素按照等原子比或者接近等原子比组成的一种高熵合金。这种合金容易形成单相FCC结构,具有高熵合金独特的四大效应,即热力学上的高熵效应、结构上的晶格畸变效应、动力学上的迟滞扩散效应以及性能上的"鸡尾酒"效应。基于这四大效应,Cantor合金具有优异的力学性能、耐磨性、耐腐蚀性以及延展性,尤其是在低温下表现出良好的断裂韧性和抗拉强度,有望替代传统合金成为未来最具发展潜力的合金。本文简单介绍了Cantor合金独特的四大效应及其常用的制备方法,对比了不同制备方法的优缺点,详细介绍了最常用的制备Cantor合金的方法——真空电弧熔炼+铜模铸造法;系统总结了Cantor合金在低温和中高温环境下的力学性能。Cantor合金的力学性能随温度的降低而逐渐提高,这是由于低温会降低合金的层错能,有助于变形孪晶的形成,变形机制由位错滑移转变为纳米孪晶。中高温度下Cantor合金的力学性能较差,且室温下该合金屈服强度不足300 MPa。同时,针对Cantor合金在中高温环境下力学性能较差的问题,介绍了目前改善该合金力学性能的常用方法,包括严重塑性变形加工和弥散颗粒的引入,其原理均为通过细化晶粒来提高合金的力学性能。另外,总结了Cantor合金组织稳定性的最新研究进展,当温度低于1073 K时,Cantor合金内部有析出相出现;当温度高于1073 K时,其仍然保持单相FCC晶体结构。最后,在此基础上对Cantor合金的发展方向进行了展望。Cantor alloy was first proposed by professor B.Cantor from the UK in 2004.It is a kind of high-entropy alloy which is composed of five principal elements including cobalt,chromium,iron,manganese and nickel with equal atomic ratio or close to equal atomic ratio.This alloy exhibits a single FCC structure and has four unique effects of high-entropy alloys,including high-entropy effect in thermodynamics,lattice distortion effect in structure,hysteresis diffusion effect in dynamics and cocktail effect in performance.Based on these four effects,Cantor alloy has excellent mechanical properties,wear resistance,corrosion resistance and ductility.Especially,it shows good fracture toughness and tensile strength at low temperature,which makes it the most promising material in the future.In this paper,the four unique effects of high-entropy alloys are briefly introduced,and the common preparation methods are compared with a summary of advantages and disadvantages of different methods.Among them,vacuum arc melting coupled with copper mold casting,the most commonly used method for Cantor alloy,is discussed in detail.The evaluation of mechanical properties with temperature of Cantor alloy is summarized.Both the tensile strength and elongation gradually increase with temperature decreasing,which is benefited from the formation of nano twins.The fault energy of Cantor alloy will decrease at low temperature and consequently the twins are easily to form,resulting in the change of deformation mechanism from dislocation slip to nano twins.However,the mechanical properties of Cantor alloy at high temperature are relatively poor.Also,the yield strength of Cantor alloy at room temperature is less than 300 MPa,which is insufficient for applications as candidate structural materials.Then research works concerning about the improvement of mechanical properties of Cantor alloy are summarized,including severe plastic deformation and introduction of dispersion particles,both of which aim to improve mechanical properties by grain refinement.Acc

关 键 词：Cantor合金 晶体结构 力学性能 组织稳定性 

分 类 号：TG146.418[一般工业技术—材料科学与工程]