Mechanism, cutting performance, and tool wear of MQL milling aluminum alloys with dual-nozzle

Although minimum quantity lubrication (MQL) machining offers excellent economic and environmental benefits, its application in actual production has been extremely restricted due to the lack of understanding of the oil mist penetration and lubrication mechanism. To reveal the oil mist penetration mechanism and process characteristics of the MQL milling process, the response surface methodology (RSM) was adopted to investigate the interaction of factors on the MQL cutting performance, optimize the process parameters, and establish the predictive models. Furthermore, the CFD simulation of the fluid field characteristics and negative pressure oil mist penetration tests were carried out to reveal the mechanism of oil mist penetration. Experimental results show that the interaction of factors has a different effect on response variables due to the various penetration capabilities, and compared with dry cutting, MQL reduced surface roughness by 34.58%, cutting temperature by 31.77%, cutting force by 21.26%, and tool wear by 60.34%. The results of CFD simulation and penetration experiments indicate that the penetration rate of oil mist is related to many factors, including the size and survival time of the capillary and the diameter and number of droplets. The findings of this work can provide valuable guidance for industry production and future investigations.