Recent Progress on Lubricant Characteristics of Minimum Quantity Lubrication (MQL) Technology in Green Cutting

As a typical sustainable cooling/lubricating method, minimum quantity lubrication (MQL) has been paid much attention to recently. However, due to the insufficiency of mechanism research, there exists blindness in the processing parameter optimization procedures. Also, it is difficult to identify the optimal match between MQL system parameters and cutting parameters to achieve the best cutting performance. As one of key factors in the engineering application of MQL technology, the lubricant characteristics, which are determined by processing parameters and physical/chemical properties of lubricant, have directly influence on the MQL cooling/lubricating performance. In order to build a quantitative relationship between the lubricant characteristics and the cutting performance, recent progress on the lubricant mist characteristics, penetration abilities and the physical/chemical properties has been reviewed. Results obtained can provide theoretical foundations for further reveal of the MQL cutting mechanism and scientific instructions for engineer application of this technology especially for the optimization of MQL system parameters and processing parameters, selecting or developing specialized MQL lubricants and the establishment of the total solution in MQL green cutting.