Study on Aerosol Characteristics of Electrostatic Minimum Quantity Lubrication and Its Turning Performance

The technology of electrostatic minimum quantity lubrication (EMQL) can not only enhance the depositing rate of lubricant droplets on the cutting area, but also increase their wetting and penetration to the contact interface, which thus improve droplet lubrication and cooling, as well as reduce concentration of the oil mist floating in the cutting environment. As a EMQL cutting system is developed, the effect of charging voltages on the diameter and distribution of lubricant droplets are investigated, and droplet wettability and deposition on the cutting interface are analyzed. The heat transfer capacity of EMQL in steady stage and its machining performance and oil-mist concentration after turning are comparatively studied. By use of tool wear analysis, the lubrication mechanism of EMQL in the cutting process is revealed. Results indicate that as lubricant charged, droplet diameter decrease and its distribution improve with an enhancement in the wettability and deposition. The cutting temperature, oil mist concentration, tool wear and workpiece surface roughness of EMQL are 14%, 8%, 37% and 28% lower than those of the traditional MQL, respectively. When EMQL is used, the improved wettability and reduced droplet diameter allow lubricant droplets to enter and cover the tool-workpiece interface more easily, which would help lubricate and cool the cutting interface, and thus achieve a better cutting performance.