大气压DBD多脉冲辉光放电Ar/NH3等离子体制备ε-Fe3N磁性润滑油及其机理研究

Atmospheric-pressure DBD plasma in an Ar/NH3 mixture is highly efficient for preparing new materials. In the Ar/NH3 DBD plasma, the key active species have been produced by NH3 decomposition and the discharge mode has been changed from filamentary discharge to multi-pulse glow discharge. In this project, atmospheric-pressure multi-pulse glow DBD plasma generated adding NH3 to Ar plasma and temperature-control technology will be applied to prepare ε-Fe3N-based magnetic lubricant, which is a clean and environmental friendly lubricant with high saturation magnetization and good fluidity. Nanoscale effect of ε-Fe3N-based magnetic lubricant can repair the cracks in a surface of friction pair; magnetic effect can solve environmental pollution of traditional lubricant and the chained-alignment pattern of ferroparticles are very conducive to keeping and antifriction of the lubricant; hence the working life of mechanical devices will been added. Nanoscale effect and magnetic effect are two main sparkles for a profitable ε-Fe3N-based magnetic lubricant. Based on in situ optical emission spectroscopy, electrical measurement and ICCD photography and numerical simulation, the key active species during the preparation process will be investigated, the plasma parameters such as electron temperature and electron density will also be analyzed and the mechanism of discharge mode will be researched for discharge parameters. According to the influence of discharge parameters on Fe and N active species, atmospheric-pressure multi-pulse glow DBD plasma and temperature-control technology will be applied to prepare ε-Fe3N-based magnetic lubricant and the preparation mechanism will be disclosed.

大气压DBD Ar/NH3等离子体是一种制备新材料的有效方法，NH3分解产生较多关键活性物种，且NH3的调节作用使等离子体的放电模式由丝状放电转变为多脉冲辉光放电。本项目旨在 Ar中掺杂电离能较低的NH3，实现大气压DBD多脉冲辉光放电等离子体协同温控技术制备饱和磁化强度高、流动性好的绿色环保ε-Fe3N磁性润滑油。它的纳米效应能修复摩擦副表面的裂缝；磁效应解决了传统润滑油的环境污染问题，且磁性颗粒的链状结构有助于润滑油的保持和减摩，提高机械装置的使用寿命；磁效应和纳米效应是其投放市场的两大亮点。采用发射光谱、电学测量、ICCD照相等手段与数值模拟相结合，探明等离子体中关键活性物种及电子温度、密度等重要参数，分析放电参数对放电模式的影响机制，以此研究放电参数对Fe、N活性物种的影响规律，揭示大气压DBD多脉冲辉光放电等离子体协同温控技术制备ε-Fe3N磁性润滑油的制备机理。

本项目采用自行研制的大气压DBD等离子体制备ε-Fe3N磁性润滑油实验装置制备了稳定的高饱和磁化强度的ε-Fe3N磁性润滑油。利用电学测量系统研究了大气压Ar/NH3/Fe(CO)5 DBD等离子体的放电电压-电流波形和Lissajous图形，大气压Ar/NH3/Fe(CO)5 DBD等离子体中存在两种放电模式，多脉冲APGD和丝状放电。采用光谱在线技术（OES）检测了大气压Ar/NH3和Ar/NH3/Fe(CO)5 DBD等离子体中的主要粒子，大气压Ar/NH3/Fe(CO)5 DBD等离子体发射光谱中主要粒子为NH、N、N+、Fe、CO、N+ 、N2、Ar、Hα、OH。等离子体中Fe和N活性基团是合成ε-Fe3N磁性颗粒的基本物质，对大气压下Ar/NH3/Fe(CO)5 DBD等离子体制备ε-Fe3N磁性润滑油提供了理论依据。NH3流量、外加电压峰峰值、表面活性剂与载液的质量比影响了ε-Fe3N磁性润滑油中磁性颗粒的组分、磁性润滑油的磁性能、颗粒尺寸和稳定性；磁性颗粒的平均粒径为11nm，饱和磁化强度达到了50.11mT。研究了ε-Fe3N磁性润滑油一阶磁浮力和二阶磁浮力，随磁场强度及磁场梯度增强，磁性润滑油的一阶和二阶磁浮力均逐渐增大。研究了磁性润滑油中磁性颗粒磁场诱导链状结构，在外加梯度磁场作用下，磁性颗粒排列成类链状结构，磁场最强处形成了复杂的链状团簇结构。研究了不同类型磁性润滑油的磁表面张力系数随磁感应强度的变化规律，随外加磁场磁感应强度的增强，磁性润滑油的磁表面张力系数增大。ε-Fe3N磁性润滑油的摩擦因数明显小于载液，“滚珠润滑”和“全膜润滑”，有效地减少了对摩擦副的磨损量。磁性润滑油的饱和磁化强度越大、固有密度越大，摩擦因数越小。随着载荷的增加，三种磁性润滑油和载液的摩擦因数均逐渐增加。随磁场强度增强，磁性润滑油的摩擦因数减小，纳米尺度效应和界面效应增加了全膜润滑的承载能力和抗磨能力。当磁场作用于磁性润滑油时，其中的纳米磁性颗粒排列成了链状结构，磁场效应更有利于形成“微轴承滚珠”效应，大大地提高了磁性润滑油的抗磨减磨能力。