Effect of Nano-Enhanced Lubricant in Minimum Quantity Lubrication Balling Milling

Minimum quantity lubrication (MQL) has been used as an alternative solution for flood cooling as well as dry machining. However, the benefit of MQL is only realized in mild machining conditions as the heat generation during more aggressive machining conditions cannot be effectively eliminated by the small amount of oil mist being applied during MQL process. To extend the applicability of MQL to more aggressive machining conditions, we have developed a potential additive to MQL lubricant. After the preliminary wetting angle measurement of the various lubricants, one commercially available MQL vegetable oil was chosen, which is then mixed in a high-speed mixer with exfoliated nanographene particles. The resulting nanoenhanced MQL lubricant was evaluated for its tribological and machining behaviors together with the suspension stability of the mixture. Friction coefficients of new nanoenhanced MQL oil were also measured in terms of loads, speeds and lubricants. Finally, MQL-ball milling tests with nanographene enhanced lubricant were performed to show a remarkable performance improvement in reducing both central wear and flank wear as well as edge chipping at cutting edge.