Enhancing Cutting Peformance Of Cemented Carbide Tools By Joint-use Of Magnetic Nanofluids And Micro-textures Under Magnetic Field

Cutting processing kept dominating in the machinery manufacturing industry.Modern manufacture with the direction of efficiency,intelligence,and greenness adopts advanced processing technology.The cutting tools as the terminal execution component of the manufacture system and the most basic cutting processing equipment will directly affect the economic benefits and the level of production technology.However,the widely used cemented carbide tools currently has problems such as severe wear,low machining efficiency and poor machining quality during cutting process.From the perspective of improving the cutting performance of the cutting tools,the micro-scale grooves parallel to the main cutting edge were fabricated on the cutting tool rake face by laser processing.Combined with magnetic field assisted cutting technology,and magnetic nanofluids were put forward in this study.The coupling effect of micro-textures and magnetic nanofluids on the cutting performance of tools under the magnetic field was explored and a novel idea for promoting high-end cutting equipment could be provided.Firstly,the feasibility of the test was judged based on the theory of magnetic field.Combined with Biot-Savart's law,a stable and adjustable magnetic field was created on the CD6140A lathe.Fe3O4 magnetic nanofluids(MN)with a mass fraction of 0.5%was selected as the cutting fluids.The optimized laser processing parameters were used to prepare 19 groups of micro-textures with different sizes and shapes on the surface of YT15 cemented carbide samples.Secondly,the influence of the coupling effect of magnetic nanofluids and micro-textures on the friction and wear properties of cemented carbide samples under the magnetic field was analyzed.According to the friction coefficient,the wear rate of the grinding ball and the wear morphology of the samples,the combination of magnetic field and magnetic nanofluids could effectively improve the lubrication performance,which could show more excellent anti-friction performance when combined with a micro-textures of the certain morphology.The corresponding anti-friction mechanism was also revealed.At the same time,the primary and secondary factors affecting the friction coefficient of micro-texture were analyzed by using range method.Thirdly,parameters of micro-textures with the best anti-friction and anti-wear effect in the friction and wear test were selected.The micro-scale grooves parallel to the main cutting edge were fabricated on the cutting tool rake face by laser processing(named TP),and for comparison the tools without surface texturing(named CT)were also prepared.The cutting tests were under the magnetic field strengths of 0 kA/m,10 kA/m,20 kA/m,30 kA/m,and 40 kA/m by conventional cutting fluids(CC)and magnetic nanofluids(MN).The results showed that compared with CT+ CC,the cutting force Fc of TP+MN was reduced by 40.1%-48.6%under different magnetic field strengths.The surface roughness Ra was reduced by 26.4%-36.3%.After cutting 1000 mm of the workpiece,the VBmax was reduced by 30.7%-45.6%.Therefore,it can be concluded that the coupling effect of magnetic nanofluids and surface micro-textures under magnetic field could effectively improve the cutting performance of cemented carbide tools.Finally,the mechanism of the coupling effect of micro-textured tool and magnetic nanofluids under magnetic field was also revealed.Analysis showed that the coupling of magnetic nanofluids and micro-textures under magnetic field could reduce cutting force,surface roughness,and improve the cutting performance of the tool.Magnetic nanofluids could be inducted by magnetic field,where magnetic nanoparticles could form a lubricating film by gathering in the cutting area to protect the surface of the tool substrate and reduce the wear of the cutting tool.With the increasing of the magnetic field strength,the magnetic nanofluids could form stable and dense lubricating film.The micro-textured tool could promote the penetration of the cutting fluids during the cutting process,accommodate the cutting fluids and lubricate the cutting area,thereby reducing the cutting force and the friction coefficient between the cutting tool and the chip.Also,the micro-textures could store some abrasive debris,preventing abrasive particles from scratching the surface of the tool substrate.In addition,magnetic nanoparticles could also fill micro-pits on the processed surface,repair damaged surfaces,remove debris from the processed surface and reduce surface roughness.By the above-mentioned mechanism,the cutting performance of YT15 cemented carbide tools can be significantly improved.