CoCrFeMoNiC_(x)中熵合金的组织及其力学和摩擦学性能  

Microstructure,Mechanical and Tribological Properties of CoCrFeMoNiC_(x) Medium-Entropy Alloys

作　　者：马文林 王府伯 张爱军[2] 孟军虎[2] 苏博[2] 韩杰胜[2,3] MA Wenlin;WANG Fubo;ZHANG Aijun;MENG Junhu;SU Bo;HAN Jiesheng(School of mechanical engineering,Lanzhou Jiaotong University,Gansu Lanzhou 730070,China;Key laboratory of science and technology on Wear and Protection of Materials,Lanzhou Institute of Chemical Physics,Chinese Academy of Science,Gansu Lanzhou 730000,China;National United Engineering Laboratory for Advanced Bearing Tribology,Henan University of Science and Technology,Henan Luoyang 471023,China)

机构地区：[1]兰州交通大学机电工程学院,甘肃兰州730070 [2]中国科学院兰州化学物理研究所中国科学院材料磨损与防护重点实验室,甘肃兰州730000 [3]河南科技大学高端轴承摩擦学技术与应用国家地方联合工程实验室,河南洛阳471023

出　　处：《摩擦学学报》2021年第6期913-923,共11页Tribology

基　　金：国家自然科学基金项目(51765029);甘肃省自然科学基金项目(20JR5RA561);高端轴承摩擦学技术与应用国家地方联合工程实验室开放基金项目(201907);宁波市科技创新2025重大专项(2019B10085)资助。

摘　　要：采用真空感应熔炼技术制备了CoCrFeMoNiC_(x)(x=0、1、2、3、4和5)系列中熵合金,研究了C元素的掺杂及其含量对合金微观组织、力学性能和摩擦学性能的影响.结果表明:CoCrFeMoNiC_(x)系列中熵合金主要由体心立方(BCC)相组成;C原子间隙固溶于BCC相,增大了合金的晶格常数,在XRD谱图中表现为衍射峰随着C含量的增加向小角度方向偏移;当C的质量分数大于2%时,BCC晶粒中有少量条状碳化物形成;随着C含量的增加,合金的硬度、强度和断裂韧性等力学性能显著提高,主要归因于C原子的间隙固溶强化效应和少量条状碳化物的出现.与此同时,合金的磨损率持续降低,表现出良好的耐磨损性能.室温下的磨损机制为磨粒磨损、塑性变形和疲劳磨损.High-entropy alloys(HEA)and medium-entropy alloys(MEA)have become one of the research focus in the field of materials science over the past decades.HEAs and MEAs usually consist of multi-principal metal elements with equal or near equal atomic ratio,and they have simple phase structures such as face centered cubic(FCC),body centered cubic(BCC)and hexagonal close packed(HCP)solid solutions.Compared with the HEAs and the conventional alloys,the MEAs exhibited superior properties such as high strength and toughness,excellent corrosion and oxidation resistance,high thermal stability,which make them have good application prospects in the industrial field.However,most of the MEAs usually contain a lot of expensive elements such as Co,Cr,Ni and Mo,which result in high cost and limit their application.Therefore,in this study,a new type of CoCrFeMoNiC_(x)MEAs with low cost and good performance has been designed and prepared.The design strategies of the MEAs were as follows:firstly,in order to achieve low-cost,the Fe content of the MEAs was more than 60%and the total content of Co,Cr,Ni and Mo was less than 40%;secondly,for improving the strength and the hardness of the MEAs,C was used for interstitial solution strengthening.The CoCrFeMoNiC_(x)(x=0,1,2,3,4 and 5)MEAs were prepared by vacuum induction melting technology,and the effects of carbon content on the microstructures,mechanical and tribological properties of the MEAs were systematically studied.The CoCrFeMoNiC_(x)MEAs with different C content mainly consisted of BCC phase.The lattice constant of the MEAs was increased by the interstitial solution of C,which caused the diffraction peaks shift to small angles in XRD spectrum with increase C content.The interstitial solid solution of C induced severe lattice-distortion in BCC phase,which could effectively improve the mechanical properties of the MEAs.In the MEA without C,all the elements were homogeneously distributed in the alloy.By comparison,when the C content was higher than 2%,small amounts of stripe carbides wer

关 键 词：中熵合金 CoCrFeMoNiC_(x)微观组织 力学性能 耐磨性 

分 类 号：TG115.5[金属学及工艺—物理冶金]