摘要
为提高高熵合金薄膜NbMoWTa的耐磨减摩性能,采用磁控溅射技术在Si基体上制备具有不同调制波长的NbMoWTa/Ag纳米多层膜,利用XRD、SEM和TEM等对纳米多层膜进行表征,分析其硬度和摩擦学性能。结果表明不同调制周期结构的纳米多层膜结晶性良好。多层膜硬度随着单层膜厚度(100~5 nm)的降低而增加(5.62~8.39 GPa),在单层膜厚度减小到20 nm时,其塑性变形机制由位错在界面处的堆积机制转变为位错穿越界面运动机制;在尺寸小于10 nm时,多层膜的硬度接近于高熵合金NbMoWTa单质膜(10.93 GPa),这可能由随着单层厚度的降低引起NbMoWTa膜与Ag膜之间界面由半共格向共格转变所引起。同时,通过摩擦磨损试验获得纯NbMoWTa薄膜的摩擦因数为0.49,磨损率为1.75×10^(-5) mm^(3)N^(-1)m^(-1);单层膜厚度为5 nm的多层膜的摩擦因数为0.23,磨损率为2.19×10^(-5) mm^(3)N^(-1)m^(-1)。在NbMoWTa中添加50%的Ag制备而成的纳米多层膜有共格强化效应,保证了其高硬度高强度的同时,由多层设计实现了耐磨和自润滑的协同控制。
In order to improve the wear resistance of high-entropy alloy film NbMoWTa and reduce its friction coefficient,NbMoWTa/Ag multilayer films with different modulation periods were deposited by magnetron sputtering on Si substrates.The characterization of nanomultilayers were systematically investigated by XRD,SEM and TEM.Its hardness and tribological properties were analyzed.The results showed that the multilayer films with different modulation periods have a high degree of crystalline.The hardness(5.62-8.39 GPa)of multilayers increases with the decrease of the individual layer thickness(100-5 nm).The plastic deformation mechanism changes from dislocations piling up against an interface mechanism to dislocation interface crossing mechanism when the thickness of monolayer decreases to 20 nm.When the thickness of monolayer is less than 10 nm,the hardness of the multilayer film is close to the high-entropy alloy film NbMoWTa(10.93 GPa).This may be caused by the transition from semi-coherent interface to coherent interface between NbMoWTa and Ag films with the decrease of individual layer thickness.Meanwhile,the experimental friction coefficient and wear rate of NbMoWTa film are 0.49 and 1.75×10^(-5) mm^(3)N^(-1)m^(-1).The experimental friction coefficient and wear rate of the multilayer film with a layer thickness of 5 nm are 0.23 and 2.19×10^(-5) mm^(3)N^(-1)m^(-1).The nanomultilayers prepared by adding 50% Ag in NbMoWTa ensures its high hardness and high strength,and realizes the coordinated control of wear resistance and selflubrication through the multilayer design.
作者
罗大微
周青
叶雯婷
韩伟超
王海丰
LUO Dawei;ZHOU Qing;YE Wenting;HAN Weichao;WANG Haifeng(State Key Laboratory of Solidification Processing,Center of Advanced Lubrication and Seal Materials,Northwestern Polytechnical University,Xi’an 710072,China)
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2021年第5期161-168,共8页
China Surface Engineering
基金
国家自然科学基金资助项目(51871184,51801161)。
关键词
纳米多层膜
硬度
高熵合金
界面结构
摩擦学
nanomultilayers
hardness
high-entropy alloy
interface structure
tribology
