Al_(0.2)Co_(1.5)CrNi_(1.5)Ti_(0.5)Mox高温耐磨高熵合金的组织结构、力学性能和摩擦学性能  

Microstructure,Mechanical Properties and Tribological Properties of Al_(0.2)Co_(1.5)CrNi_(1.5)Ti_(0.5)Mox High-Temperature Wear-Resisting High Entropy Alloy

作　　者：邱玉新 张爱军[2] 辛本斌 孟军虎[2] 吴有智[1] QIU Yuxin;ZHANG Aijun;XIN Benbin;MENG Junhu;WU Youzhi(School of Material Science and Engineering,Lanzhou University of Technology,Gansu Lanzhou 730050,China;State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Science,Gansu Lanzhou 730000,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [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

出　　处：《摩擦学学报》2023年第12期1381-1392,共12页Tribology

基　　金：国家自然科学基金项目(52101185);兰州化物所青年科技工作者合作基金项目(HZJJ20-09);中国科学院材料磨损与防护重点实验室青年基金项目(SYSQJ-2021-2)资助。

摘　　要：使用真空电弧熔炼技术制备了Al_(0.2)Co_(1.5)CrNi_(1.5)Ti_(0.5)Mox(x=0.0,0.1,0.2,0.3,0.4)高熵合金,研究了Mo含量对该高熵合金组织结构、力学性能和摩擦学性能的影响规律及其作用机制.Al0.2Co1.5CrNi1.5Ti0.5高熵合金由FCC相和有序AlNi3相组成,Mo元素添加后促进形成σ相.较大原子半径的Mo元素引发的晶格畸变效应和σ硬质相析出引起的第二相强化效应赋予高熵合金优良的力学和摩擦学性能.随着Mo含量的提高,合金的硬度增加了40.4%,屈服强度增加了32.1%.对该合金的摩擦磨损性能进行研究,发现Mo元素的添加显著改善了高熵合金的摩擦学性能,尤其是当Mo的摩尔比为0.4时,高熵合金室温磨损率为2.62×10^(-6)mm^(3)/(N·m),800℃时的磨损率为6.23×10^(-7)mm^(3)/(N·m),分别相对于不含Mo元素的高熵合金降低了83.4%和89.7%.室温耐磨性能的改善得益于高熵合金强度和硬度的提升,氧化釉质层的形成和良好的高温力学性能对高温摩擦学性能的提高起到了关键作用.The Al_(0.2)Co_(1.5)CrNi_(1.5)Ti_(0.5)Mox(x=0 to 0.4)high entropy alloy was prepared by vacuum arc melting,and the influence of Mo element on the microstructure,mechanical properties and tribological properties of the high entropy alloy was analyzed.Moreover,the wear mechanism of the high entropy alloy was researched.The Al0.2Co1.5CrNi1.5Ti0.5 high entropy alloy consists of FCC phase and ordered AlNi3 phase.The addition of Mo caused the segregation of Cr and Mo,and promotes the formation of hardσphase through the in-situ reaction of Cr and Mo atoms.With the increase of Mo content,the content ofσphase also increases gradually,and the addition of Mo makes the high entropy alloy produce obvious lattice distortion.The lattice distortion effect induced by the Mo with larger atomic radius and the precipitated phase strengthening effect of the hardσphase endow the high entropy alloy with excellent mechanical and tribological properties.As the molar content of Mo increased from 0 to 0.4,the hardness of high entropy alloy was increased from 520 HV to 730 HV by 40.4%,and the yield strength increased by 32.1%from 1060 MPa to 1400 MPa.However,the hardσphase is a brittle phase and cannot deform as the FCC phase with better plasticity at the same time,which leads to a significant decrease in the plasticity and toughness of high entropy alloys.The tribological performance of the high entropy alloy at RT~900℃is characterized by ball-on-disc high temperature tribometer.The addition of Mo elements significantly improved the tribological performance of the high entropy alloy,especially when the Mo content was 0.4 mol,the wear rate at RT and 800℃was 2.62×10^(-6)mm^(3)/(N·m)and 6.23×10^(-7)mm^(3)/(N·m),respectively,which improved by 83.4%and 89.7%compared with that of high entropy alloy without Mo.And the wear resistance is better than Inconel 718 and Stellite 6 alloys.The improvement of wear resistance was attributed to the increased microhardness and yield strength of the high entropy alloy at room temperature,and the w

关 键 词：高熵合金 微观组织 力学性能 摩擦学性能 高温耐磨机制 

分 类 号：TH117.1[机械工程—机械设计及理论] TG115.5[金属学及工艺—物理冶金]