Metal cutting fluids in flood condition does not meet the urgent needs of emission cutting and carbon reduction, minimum quantity lubrication (MQL) is an effective alternative to flood lubrication. Nevertheless, the micro-droplets produced by pneumatic atomization MQL have poor infiltration and wetting properties, which cannot fully exert the film-forming and heat transfer performance of lubricant. The unique empowering mechanism of electrostatic atomization can not only solve the above technical bottleneck, but also realize parametric control of the droplets. Previously, the improvement of tool wear and surface integrity of electrostatic atomization have been preliminarily verified by experimental studies. However, the application principle of electrostatic atomization in the manufacturing process is ambiguous, which limits its further development and industrial application. Especially the in-depth understanding of the action mechanism of the high temperature and high pressure contact interface is difficult and meaningful. More importantly, electrostatic atomization-assisted MQL machining has not been systematically reviewed. In this review, firstly, an analysis of the critical devices, common media (nano-biolubricants) and empowering mechanisms is presented. Subsequently, the excellent machining performance of nano-biolubricants was quantitatively evaluated by comparing with flood, revealing its advanced lubrication and heat transfer mechanism. Furtherly, the excellent machining performance was assessed based on the enhanced penetration, infiltration and film formation properties of electrostatic atomization, with a 42.4% reduction in tool wear and a 47% improvement in machined surface Ra compared to pneumatic atomization. Finally, the limitations of current electrostatic atomization and green lubrication technologies are analyzed and the future trends (e.g. new processes and multi-process coupling) are foreseen. The aim of this paper is to provide a comprehensive review and critical assessment of the existing understanding, which can be used by scientists to gain insight into the mechanism of action, the theoretical basis, machining performance and development direction of new electrostatic atomization processes.

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