Investigation of cryogenic cooling effect in reaming Ti-6AL-4V alloy

This research article is based mainly on the investigation of the effect of cryogenic machining, while reaming Titanium grade 5 alloy (Ti-6Al-4V) material. Cutting speed (V-c) and feed rate (f) are two input parameters at three different levels for a constant depth of the hole. The output parameters considered by using a cryogenic LN2 cooling compared to a conventional flood cooling are torque (M-t), thrust force (F-t), cutting temperature (T), quality of the hole (circularity and cylindricity), surface roughness (R-a) and chip morphology. The results show cryogenic liquid nitrogen (LN2) cooling resulting in 15-31% reduction in the cutting temperature, 23-57% reduction in the thrust force and 14-65% reduction in torque. Higher surface roughness, circularity (Cir) and cylindricity (Cyl) were observed in the cryogenic LN2 cooling condition. Furthermore, better chip breakability was observed in the cryogenic LN2 cooling condition. No drastic change in the microstructure was observed in both flood and cryogenic LN2 cooling. Increase in microhardness by 10-16% and 8-19% in cryogenic LN2 cooling over flood cooling was observed.