Design of an internally cooled green tubular channel for turning application

Cooling machining has recently been aggressively researched in turning applications for difficult-to-cut materials. However, it is important to note that the supply of cutting fluids increases machining costs and constitutes potential hazards to human health and the environment. The present investigation has established four innovative strategies for delivering cutting fluids to the flank face via the MQL system. A tubular channel was created to fit a copper tube in a shim to circulate cutting fluids in the new internally cooled system. For an externally cooled system, novel micro-holes with a multi-directional spray cooling system have been designed. Novel approaches were devised for the upper and lower parts of the flank surface of cutting fluids in both systems. The effectiveness of four cooling strategies was compared by turning Hastelloy-B3 material with the supply of coconut oil in the MQL system. The experimental results showed that internal cooling systems (Condition 3: top face and Condition 4: Bottom face) showed a reduction in cutting force by 47.7%, 44%, and 42.5%, reduced cutting temperature by 10.2%, 7%, and 8%, surface roughness by 24%,12%, and 3.7% and flank wear by 49% compared to external cooling systems. In addition, the internal cooling system (Condition 4) showed a decreased value of chip width by 0.6297 mm, friction coefficient by 0.314, and shear angle by 31.17° for the above machinability improvement. Response surface methodology is used to correlate cutting variables with several process responses. Therefore, novel sustainable cooling technologies may increase machinability in other hard-to-machine materials.