静电雾化微量润滑研究进展与应用

Research Progress and Application of Electrostatic Atomization Minimum Quantity Lubrication

微量润滑作为替代浇注式供液冷却的可行性方案之一,得到了数十年的发展。然而,气动雾化微量润滑雾滴的表面能逐渐降低;射流的穿透力、吸附力和浸润性能不足,雾滴的漂移和飞溅丧失严重,加大了对环境的污染。静电雾化微量润滑是解决工业生产应用面临技术瓶颈和环保压力的有效方式。首先,系统综述了静电雾化微量润滑关键装置、赋能原理与绿色雾化介质(纳米生物润滑剂)。其次,揭示了微液滴的雾化性能对切削区浸润性能的影响机制,并从荷电液滴静力学的角度阐述了静电雾化微量润滑优异的雾化性能,通过表征雾化介质的荷电性能分析了不同参数对雾化能力的影响机制。进一步地,基于纳米生物润滑剂的脂肪酸分子结构、黏度等理化性质,以及荷电液滴表面状态、空间多能场等,揭示了静电雾化微量润滑改善液滴浸润、渗透以及成膜性能的作用机制,并综述了其在车削、铣削、磨削等工况下对降低刀具磨损、提高加工表面质量的优异性能。在此基础上分析得到:静电雾化优异的雾化特性以及纳米生物润滑剂独特的润滑传热机制,不仅降低了加工环境油雾浓度,还提升了微量润滑的加工性能,具体表现在,与传统微量润滑相比PM2.5/PM10降低约6.2%~68.3%,刀具寿命增加约48.1%~100%,Ra降低约12.6%~39.3%。最后,展望了未来的发展趋势,以此希望为制造业双碳转型提供技术支撑和理论参考。

Minimum quantity lubrication(MQL)has been developed for decades as a viable alternative to flood lubrication.However,the surface energy of the micro-droplet produced by pneumatic atomization MQL gradually decreases;the penetration,adsorption and wetting properties of the jet are insufficient,and the drift and splash loss of the droplets are serious,increasing the pollution to the environment.Electrostatic atomization MQL is an effective way to solve the technical bottleneck and environmental pressure faced by industrial production applications.In this review,firstly,a systematic review of the key devices,empowerment principles and green atomization medium(nano-bio-lubricant)of electrostatic atomization MQL are presented.Subsequently,the influence mechanism of the atomization performance of the micro-droplets on the wetting performance of the cutting area is revealed,the excellent atomization performance of the electrostatic atomization is expounded from the perspective of the statics of the charged droplets,and the influence mechanism of different parameters on the atomization performance is analyzed by characterizing the charging performance of the atomization medium.Furtherly,based on the fatty acid molecular structure,viscosity and other physicochemical properties of nano-biolubricants,as well as the surface state of charged droplets,spatial multi-energy field,etc.,the mechanism of electrostatic atomization MQL to improve droplet infiltration,wetting and film-forming properties was revealed,and its excellent performance in reducing tool wear and improving the quality of machined surface under turning,milling,grinding and other working conditions is reviewed.On this basis,it is considered that the excellent atomization characteristics of electrostatic atomization and the unique lubrication and heat transfer mechanism of nano-biolubricants can not only reduce the oil mist concentration in the machining environment,but also improve the machining performance of MQL.Specifically,compared with traditional MQL,PM2.5/PM10 is reduced by about 6.2%-68.3%,tool life is increased by about 48.1%-100%,and Ra is reduced by about 12.6%-39.3%.Finally,the future development trend is foreseen in the hope of providing technical support and theoretical reference for the carbon peaking and carbon neutrality transformation of manufacturing industry.