Investigation of the effects of nanoparticle added cutting oils on machining performance in the drilling of hastelloy X super alloy

The cutting fluid used in metal cutting operations shows adversely affects on the environment, human health and total production costs. For this purpose, it is important to the amount of cutting fluid need to be minimized or ecological cooling/lubrication methods can be prefer. In this study, ecological cooling/lubrication methods were examined and effects of dry, MQL, Mono and Hybrid Nano MQL cooling/lubrication conditions on thrust force, torque, hole quality (surface roughness, diameter deviations, roundness and cylindricity), cutting temperature, burr height, tool wear and tool life were investigated when drilling of nickel based super alloy Hastelloy X. Nanofluids were prepared by adding 0.6 vol% graphene nanoplatelets (GNP) and hexagonal boron nitride (hBN) nanoparticles. Sodium Dodecyl Sulfate (SDS) and Gum Arabic (GA) added by 0.25 wt% as surfactants into the nanofluids for homogeneous and stable mixtures. In drilling experiment, 5 mm diameter TiAlN coated carbide drills as cutting tools, two different cutting speeds (20 and 30 m/min), two different feed rates (0.04 and 0.06 mm/rev) and a costant drilling depth (13.5 mm) was used. The best cutting force, torgue, hole quality, burr height, and tool wear results were obtained under SDS added hBN/GNP hybrid cutting condition whereas the best cutting temperature results were achieved under hBN/GNP hybrid cutting condition without surfactants. The maximum flank wear of the drill was measured as 0.281 mm after 10 holes under dry cutting condition, whereas the minimum flank wear was measured as 0.135 mm after 60 holes under hBN/GNP-SDS cutting condition. The hBN/GNP-SDS cutting condition improved by 51.96% compared to the dry cutting condition in terms of tool wear. The hBN-SDS showed better cutting performance among the mono nanofluids cutting condition, while the hBN/GNP-SDS showed better cutting performance among the hybrid nano fluids cutting condition. Also, when the surfactants added to nanofluids were evaluated, it was determined that the SDS performed better than the GA in terms of cutting performance.