Direct observation of fluid action at the chip-tool interface in machining

The present study seeks to realize an improved understanding of the action of cutting fluid through direct observation of the chip-tool interface. That is, using transparent tools made of sapphire in conjunction with a high-speed, CCD-based imaging system, the chip-tool contact condition and its evolution in the presence of cutting fluid are directly observed during 2-D orthogonal machining of pure lead and Al6061-T6. Then, spatial and temporal analysis of the images of the chip-tool interface is made for measuring the contact length and velocity profile along the tool rake face, and the contact conditions are correlated with the cutting forces measured. The results are compared with those made when cutting dry to clarify the effects of cutting fluid action, and a picture of the action of cutting fluid at the chip-tool interface is presented finally.