The Coupling Effect Of Micro-textures And Nanofluids On Cutting Performance Of Cemented Carbide Tools

As an important part in machinery manufacturing industry,the cutting technology has been widely used in aerospace,automotive and mold manufacturing industries,and promote the development of the machinery manufacturing industry.However,the tool wear is still the urgent problem in machining hard-cutting materials,such as machining titanium alloy.In recent years,the surface textures have been emerged as an effective method in improving the tools cutting performance.In addition,some researches show that the excellent lubrication performance and better thermal conductivity properties of the cutting fluids can be achieved by the addition of nanoscale particles into conventional cutting fluids.Hence,to maximum exhibit the performance of the cutting tools,many researches have been done by combining the surface texture technology and nano lubrication technology.Based on the above research hotspot.Through fabricating micro-groove textures on tool rake face,and using nanofluids as lubricant.This paper proposed coupling nanofluids and surface textures in machining titanium alloy.And,the coupling effect mechanism was also revealed.The primary work could be concluded as follows:Firstly,two-step method was used to prepare the Fe3O4 nanofluids(NC)with a mass fraction of 0.5%.The Fe3O4 nanoparticles were added to the water-based cutting fluids(CC).After that,the oil acid was added under ultrasonic vibration and magnetic stirring so as to get a stable suspension fluid.The dispersing effect of Fe3O4 nanofluids was evaluated by sedimentation method.Results obtained that the prepared Fe3O4 nanofluids had better stability.And,the Nd:YAG laser was employed to fabricate various parameters and morphologies of surface textures on YG6X cemented carbide sample.Secondly,the friction and wear test was carried out.The lubrication performance of nanofluids was investigated by measuring the friction coefficient,the wear behaviors of the sample and the wear rate of the ball.It was found that the nanofluids could improve the lubrication performance of the water-based fluids.Excellent properties of anti-friction and anti-wear could be achieved by combining with nanofluids and surface textures.And,the corresponding anti-friction mechanism was also revealed.Thirdly,the surface textured tools were fabricated(TP).And,the un-textured tool were also used for comparison.The parameters of the surface textures were selected from the friction and wear test,which behaved the better lubrication performance among all.To revealed and explored the coupling effect of nanofluids and surface textures on tools cutting performance,the cutting experiments were also carried out.The results of cutting forces,tools life,the machined surface roughness,tool wear behaviors and tool wear rate were summarized and analyzed.It was found that the tools cutting performance could be significantly improved by combining the nanofluids and surface textures.Finally,the coupling effect mechanism of nanofluids and surface textures was analyzed.The combination of textures and nanofluids is not a simple superposition,which behaves a coupling effect.The coupling effect can be summarized as following:in cutting process,the existence of surface textures can facilitate the lubricant penetrate into the tool-chip contact interfaces.Owning to the better wettabilities of nanofluids droplet on tool rake face,the nanofluids can immediately coverage and spread on the textured rake face,which can increase the lubrication region.Moreover,nanoparticles of the nanofluids show better properties of ductility and flexibility can be squeezed by the high extrusion force in machining when compared with other lubricants.As a result of this effects,a protective physical lubrication film can be quickly and continually formed in the machining zone.By the virtue of the nanoparticle embedded into the protective physical lubrication film,which behaved the rolling-effect.And,the friction condition between the friction pairs could transform from sliding friction into rolling friction with the existence of the nanoparticles.Meanwhile,the damage of the textures can be decreased with the existence of the protective lubrication film,and the texture can continuously have a better effect on cutting tools.In conclusion,because of the coupling effect of nanofluids and surface textures,the tools cutting performance can be improved significantly.