Machining and environmental effects of electrostatic atomization lubrication in milling operation

Abstract

The disadvantages of minimum quantity lubrication (MQL) are its poor cooling capability and environment and health hazard as a result of mist formation, resulting in considerable limitations on its widespread application. There is an urgent need to improve its cooling/lubrication performance and environmental performance. Electrostatic atomization is a method where the liquid is electrostatic charged and broken into fine charged droplets by means of electrical forces. This paper investigated the role of electrostatic atomization lubrication (EAL) and nanofluid electrostatic atomization lubrication (NFEAL) on tool wear in end milling of Ti-6AI-4V alloy, and evaluated their environmental performance in non-machining experiments in terms of oil mist concentrations of PM10 and PM2.5. For this research, electrostatic atomization milling system was designed and fabricated. A comparison with the results obtained under MQL condition is also provided. The experimental results show that there was a considerable reduction in tool wear and oil mist concentration for EAL and NFEAL as compared with MQL condition. Furthermore, NFEAL was more effective than EAL for reducing tool wear. But NFEAL yielded slightly higher oil mist concentration than EAL. Therefore, EAL and NFEAL seem to be potential cooling/lubricating approaches for the machining substituting MQL from view point of machining performance, health, and environment.