Fundamental Research on Hobbing with Minimal Quantity Lubrication of Cutting Oil Comparison of Cutting Performance with Dry Cutting

-This paper compares the cutting performance of minimal quantity lubrication (MQL) system with dry cutting in terms of flank wear, crater wear and finished surface roughness when using various kinds of cutting tools. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results obtained are summarized as follows. (1) When using an uncoated tool, TiNand (Al, Ti) N-coated tools without coating on the rake face, and fully TiNand (Al, Ti) N-coated tools, MQL decreases the flank wear, crater wear and finished surface roughness compared with the wear and the roughness by dry cutting, particularly at the high cutting speed of 159 m/min. The reason suggested is the lubricating properties improved even with an extremely small quantity of cutting oil, which reduces the occurrence of deposited metal on the cutting edge. (2) With both the fully TiNand (Al, Ti) N-coated tools, the MQL system showed better cutting performance in terms of reduced tool wear and reduced finished surface roughness compared with that by dry cutting; in particular, the fully (Al, Ti) N-coated tool is suitable for an MQL system in hobbing.