Study On Tribological Characteristics Of Micro/Nano Textured Tool With Bionic Hydrophobic Surface

In the process of cutting metal,there is severe friction between the tool and the chip,which increases the cutting force,cutting heat and deformation of the workpiece.The application of surface texture on the tool can reduce the friction in the metal cutting process,reduce the bonding between the tool and the chip,inhibit the growth of built-up tumor,and improve production efficiency.With the in-depth research on wettability,surfaces with hydrophobic properties have shown broad application prospects in many areas of industrial production and daily life,such as self-cleaning,flow drag reduction,and oil-water separation.In this article,surface texture technology and wettability control technology were combined and applied to the tool surface.The friction and wear characteristics of surfaces with different surface wettability,different texture depths and texture arrangements are studied.The purpose is to explore a new method to reduce friction by using the wettability micro-nano texture of the friction surface,and to provide a theoretical basis for the design of bionic tribology.In terms of simulation,this paper uses SOLIDWORKS software to establish three-dimensional models of triangle texture,semicircular ring texture,and V-shaped texture.By imitating the structure of fish scales,the drag reduction model is applied to the arrangement of micro-nano textures.FLUENT software is used for fluid simulation of cutting process to simulate the influence of micro-nano texture shape and arrangement on dynamic pressure effect.The simulation results show that the dynamic pressure value generated by the texture unit with a depth of 10 ?m is about twice higher than that of the texture unit with depth of 20 ?m and 30 ?m,and the dynamic pressure effect on the lubricating film is obvious.The dynamic pressure effect of the triangular texture is better than that of the V-shape and the semicircular ring.The dynamic pressure generated by the bionic staggered triangular and V-shaped textures is higher than the dynamic pressure generated by the symmetrical texture.The flow rate of the texture of the biomimetic arrangement is increased faster than that of the texture of the array arrangement,which has a better drag reduction effect.In terms of friction and wear experiments,YT15 cemented carbide is used as the substrate and femtosecond laser processing technology is used to prepare micro-nano textures with different depths and different arrangements on the surface.The fluorination treatment technology is used to control the surface wettability,and a micro-nano texture specimen with a hydrophobic effect surface is prepared.The RTECMFT-50 friction and wear tester was used for friction and wear experiments.According to the results of comparative experiments,the shallower micro-nano texture unit can only generate a small hydrodynamic pressure and the texture is quickly abraded as the wear process.Under high-loading and high-frequency conditions,a specimen with a texture depth of 7 ?m can effectively reduce the friction coefficient,but it cannot avoid cavitation pits caused by cavitation.The specimen with a texture depth of 10 ?m produces a higher hydrodynamic pressure and has better abrasion resistance.Compared with the wear morphology of the array texture surface,only shallow wear scars appear on the surface of the bionic texture texture.And the extruded peeling area is small,mainly concentrated on the edge of the texture base.It shows that the triangular texture of the bionic arrangement reduces the friction resistance and has better abrasion resistance.The hydrophobic texture surface has low surface free energy and micro-nano texture.Low surface energy can reduce adhesion and friction resistance.The micro-nano texture can generate hydrodynamic pressure,store hard particles and reduce abrasive wear.Under the synergistic effect,the surface exhibits excellent anti-friction and wear resistance.In the cutting experiment,a bionic textured tool and a hydrophobic textured tool were designed and prepared.CDE6140 A type traditional lathe is used to carry out the comparative test of cutting 45 steel.During the cutting test,the three-way turning dynamometer was used to measure the cutting force to calculate the average friction coefficient of the rake face.The results show that at low cutting speeds,the three-way cutting force on the surface of the hydrophobic textured tool is lower than that of the textured tool and the ordinary tool.A large amount of iron filings and furrows appear on the rake face of ordinary tools.There is only a small amount of iron filings on the rake face of the textured tool.The rake face of the hydrophobic textured tool is basically free of furrows and iron filings.The synergistic effect of the low surface energy and micro-nano texture of the hydrophobic texture tool further improves the anti-adhesion and wear resistance of the tool.