Metal cutting fluids(MCFs)under flood conditions do not meet the urgent needs of reducing carbon emission.Biolubricant-based minimum quantity lubrication(MQL)is an effective alternative to flood lubrication.However,pn...Metal cutting fluids(MCFs)under flood conditions do not meet the urgent needs of reducing carbon emission.Biolubricant-based minimum quantity lubrication(MQL)is an effective alternative to flood lubrication.However,pneumatic atomization MQL has poor atomization properties,which is detrimental to occupational health.Therefore,electrostatic atomization MQL requires preliminary exploratory studies.However,systematic reviews are lacking in terms of capturing the current research status and development direction of this technology.This study aims to provide a comprehensive review and critical assessment of the existing understanding of electrostatic atomization MQL.This research can be used by scientists to gain insights into the action mechanism,theoretical basis,machining performance,and development direction of this technology.First,the critical equipment,eco-friendly atomization media(biolubricants),and empowering mechanisms of electrostatic atomization MQL are presented.Second,the advanced lubrication and heat transfer mechanisms of biolubricants are revealed by quantitatively comparing MQL with MCF-based wet machining.Third,the distinctive wetting and infiltration mechanisms of electrostatic atomization MQL,combined with its unique empowering mechanism and atomization method,are compared with those of pneumatic atomization MQL.Previous experiments have shown that electrostatic atomization MQL can reduce tool wear by 42.4%in metal cutting and improve the machined surface Ra by 47%compared with pneumatic atomization MQL.Finally,future development directions,including the improvement of the coordination parameters and equipment integration aspects,are proposed.展开更多
Minimum quantity lubrication(MQL)is a relatively efficient and clean alternative to flooding workpiece machining.Electrostatic atomization has the merits of small droplet diameter,high uniformity of droplet size,and s...Minimum quantity lubrication(MQL)is a relatively efficient and clean alternative to flooding workpiece machining.Electrostatic atomization has the merits of small droplet diameter,high uniformity of droplet size,and strong coating,hence its superiority to pneumatic atomization.However,as the current research hotspot,the influence of jet parameters and electrical parameters on the average diameter of droplets is not clear.First,by observing the shape of the liquid film at the nozzle outlet,the influence law of air pressure and voltage on liquid film thickness(h)and transverse and longitudinal fluctuations are determined.Then,the mathematical model of charged droplet volume average diameter(VAD)is constructed based on three dimensions of the liquid film,namely its thickness,transverse wavelength(λ_(h)),and longitudinal wavelength(λ_(z)).The model results under different working conditions are obtained by numerical simulation.Comparisons of the model results with the experimental VAD of the droplet confirm the error of the mathematical model to be less than 10%.The droplet diameter distribution span value Rosin–Rammler distribution span(R.S)and percentage concentrations of PM10(particle size of less than 10μm)/PM2.5(particle size of less than 2.5μm)under different working conditions are further analyzed.The results show that electrostatic atomization not only reduces the diameter distribution span of atomized droplets but also significantly inhibits the formation of PM10 and PM2.5 fine-suspension droplets.When the air pressure is 0.3 MPa,and the voltage is 40 kV,the percentage concentrations of PM10 and PM2.5 can be reduced by 80.72%and 92.05%,respectively,compared with that under the pure pneumatic atomization condition at 0.3 MPa.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51975305,51905289,52105457 and 52105264)National key Research and Development plan(2020YFB2010500)+2 种基金Key projects of Shandong Natural Science Foundation of China(Grant Nos.ZR2020KE027,ZR2020ME158 and ZR2021QE116)Major Science and technology innovation engineering projects of Shandong Province(Grant No.2019JZZY020111)Source Innovation Project of Qingdao West Coast New Area(Grant Nos.2020-97 and 2020-98).
文摘Metal cutting fluids(MCFs)under flood conditions do not meet the urgent needs of reducing carbon emission.Biolubricant-based minimum quantity lubrication(MQL)is an effective alternative to flood lubrication.However,pneumatic atomization MQL has poor atomization properties,which is detrimental to occupational health.Therefore,electrostatic atomization MQL requires preliminary exploratory studies.However,systematic reviews are lacking in terms of capturing the current research status and development direction of this technology.This study aims to provide a comprehensive review and critical assessment of the existing understanding of electrostatic atomization MQL.This research can be used by scientists to gain insights into the action mechanism,theoretical basis,machining performance,and development direction of this technology.First,the critical equipment,eco-friendly atomization media(biolubricants),and empowering mechanisms of electrostatic atomization MQL are presented.Second,the advanced lubrication and heat transfer mechanisms of biolubricants are revealed by quantitatively comparing MQL with MCF-based wet machining.Third,the distinctive wetting and infiltration mechanisms of electrostatic atomization MQL,combined with its unique empowering mechanism and atomization method,are compared with those of pneumatic atomization MQL.Previous experiments have shown that electrostatic atomization MQL can reduce tool wear by 42.4%in metal cutting and improve the machined surface Ra by 47%compared with pneumatic atomization MQL.Finally,future development directions,including the improvement of the coordination parameters and equipment integration aspects,are proposed.
基金This research was financially supported by the National Natural Science Foundation of China(Grant Nos.52105457 and 51975305)the National Key R&D Program of China(Grant No.2020YFB2010500)+1 种基金Major Science and Technology Innovation Engineering Projects of Shandong Province(Grant No.2019JZZY020111)General project of Liaoning Provincial Department of Education(Grant No.LJKMZ20220971).
文摘Minimum quantity lubrication(MQL)is a relatively efficient and clean alternative to flooding workpiece machining.Electrostatic atomization has the merits of small droplet diameter,high uniformity of droplet size,and strong coating,hence its superiority to pneumatic atomization.However,as the current research hotspot,the influence of jet parameters and electrical parameters on the average diameter of droplets is not clear.First,by observing the shape of the liquid film at the nozzle outlet,the influence law of air pressure and voltage on liquid film thickness(h)and transverse and longitudinal fluctuations are determined.Then,the mathematical model of charged droplet volume average diameter(VAD)is constructed based on three dimensions of the liquid film,namely its thickness,transverse wavelength(λ_(h)),and longitudinal wavelength(λ_(z)).The model results under different working conditions are obtained by numerical simulation.Comparisons of the model results with the experimental VAD of the droplet confirm the error of the mathematical model to be less than 10%.The droplet diameter distribution span value Rosin–Rammler distribution span(R.S)and percentage concentrations of PM10(particle size of less than 10μm)/PM2.5(particle size of less than 2.5μm)under different working conditions are further analyzed.The results show that electrostatic atomization not only reduces the diameter distribution span of atomized droplets but also significantly inhibits the formation of PM10 and PM2.5 fine-suspension droplets.When the air pressure is 0.3 MPa,and the voltage is 40 kV,the percentage concentrations of PM10 and PM2.5 can be reduced by 80.72%and 92.05%,respectively,compared with that under the pure pneumatic atomization condition at 0.3 MPa.
