Effect of micro-texture/hybrid nanofluid synergistic MQL on the turning Inconel 718

In order to reveal the synergistic mechanism of tool micro-texture and nanofluid, experimental studies on MQL turning of Inconel 718 high temperature alloy with micro-pit/micro-groove texture on flank and rear surfaces and MoS₂, multi-walled carbon nanotubes (MWCNTs) and MoS₂/MWCNTs hybrid nanofluid were carried out. The micro-holes and micro-groove textures were fabricated on the cutting tool's flank and rear surfaces using picosecond laser technology. The textures were characterized using a laser confocal microscope. MoS₂, MWCNTs, MoS₂/MWCNTs mixed nanofluids were prepared, and the viscosity, thermal conductivity and surface tension were determined. The synergistic influence of nanofluids and microtextures on wettability was tested. Orthogonal cutting experiments with four factors and four levels of cutting speed, microtextures on the front face, microtexture on the back face and type of nanofluid were carried out and evaluated in terms of cutting force, cutting temperature, three-dimensional surface roughness and chip deformation coefficient. The experimental results showed that the cutting force and chip deformation were the lowest for MoS₂ nanofluid, parallel groove microtextures on the flank surface and round pit microtextures on the rear surface; the surface roughness was the lowest for MoS₂/MWCNTs hybrid nanofluid, parallel groove microtextures on the flank surface and round pit microtextures on the rear surface.