| Grinding process plays a more and more important status on the modernmechanical processing. But the mostly processing method of grinding processing isnegative rake Angle processing, so a large amount of heat will produce in the process ofgrinding which lead to the working environment of the grinding area become very bad.So flooding grinding process is widely used in the machining process to improve theworkpiece machining accuracy and surface quality. But a large number of grinding fluidis used which increases the cost of production and causes serious harm to theenvironment and human, so flooding grinding can not meet the requirements of thecurrent green machining. Dry grinding process and minimum quantity lubrication(MQL) grinding process meet the requirements of environmental protection, but havingpoor cooling and lubricating effect, and it is difficult to obtain a good workpiece surfaceintegrity especially to difficult-to-machine materials process. MQL technology bynanoparticles jet (Nano-MQL) can well solve problem of heat transfer in the grindingzone, while enhancing the lubricating properties of grinding zone.This paper researches the lubrication mechanism of Nano Particle in Jet MQLGrinding, especially researches the lubrication mechanism of base oil and nano particlewhich used in Nano Particle in Jet MQL Grinding. The specific research work is asfollows:1. For high energy density in the grinding zone of grinding processing， floodinggrinding, dry grinding, MQL grinding and grinding using MQL by nanopaticles jet aresystematically analyzed. On the basis of domestic and foreign research present situationof MQL machine，nanofluids，grinding using MQL by nanopaticles jet and Grindingfluid field characteristics， the nanoparticles jet trace grinding characteristics of flowfield on the lubrication mechanism of lubrication research is put forward.2. Combining with the liquid surface tension，viscosity and the aerodynamics，theliquid atomization principle is analyzed, mathematical model of liquid atomization is setup. The atomization characteristics of fluid nozzle were studied, the theoretical model and empirical model of nozzle spray droplet size distribution is given.3. The lubricating mechanism of grinding wheel/workpiece interface using MQLby nanopaticles jet is studied, Film forming characteristics of MQL baseoil and nanoparticles is analyzed, lubrication antifriction mechanism of “Roll-boll” isanalyzed. For MQL grinding, the influence of processing parameters (Grinding wheelspeed, nozzle position, MQL base oil and kinds of nanoparticles, etc) on the lubricationeffect and its change rule is analyzed.4. Using CFD simulation software Fluent, the downstream flow field of the spraynozzle is modeling and simulation analyzed. The axial velocity and radial velocity ofcontinuous phase and discrete phase in the downstream flow field is established. Theinfluence rule of working parameters on axial velocity, droplet size distribution andlocation distribution is studied.5. Using high speed camera system i-speed TR, Spray nozzle exit area is shot. Thechange rule of liquid atomization process, droplet size and droplet velocity variation isstudied, and comparing with theoretical analysis.6. Nickel base alloy is used in surface grinding experiment. Specific grindingforce，specific grinding energy，coefficient of friction and workpiece surface quality offour kinds of lubrication condition grinding process is contrastive analyzed. the validityof grinding using MQL by nanopaticles jet is verified. For further grindingexperiments，different kinds of MQL base oil, nanoparticles, nanoparticle concentration,compressed air pressure, gas liquid ratio and liquid flow rate are tested, the bestlubrication parameters of nickel base alloy grinding is given. |
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