The Mechanism Of Convective Heat Transfer And Experimental Investigation In Grinding Nickel-base Superalloy By Nanoparticle Jet MQL

Grinding process is an essential machining process. Large amount of heat isgenerated and transmitted to the surface of workpiece, which results in surface burning.So many kinds of cooling and lubrication technology are widely used in the machiningprocess to reduce the influence on the surface quality of workpiece from grinding heat.A large number of grinding fluid is used in flooding grinding process and causes seriouspollution to the environment, which can not meet the requirements of the current greenmachining. Dry grinding process and minimum quantity lubrication (MQL) grindingprocess meet the requirements of environmental protection, but having poor cooling andlubricating effect, and it is difficult to obtain a good surface quality. MQL technology bynanoparticles jet can well solve problem of heat transfer in the grinding zone, whileenhancing the lubricating properties of grinding zone.This paper researches the cooling and lubrication performance of four kinds ofcooling and lubrication technology in view of the grinding of nickel base alloy GH4169,MQL technology by nanoparticles jet is emphatically studied. The correspondingmathematical model is established according to the principle of grinding. ABAQUS isused in simulation, the simulation results and experimental verification are used tocontrast cooling and lubrication performance and workpiece surface quality of floodinggrinding process, dry grinding process, MQL grinding process, MQL technology bynanoparticles jet grinding process. A best effect of cooling and lubrication solutions isgot. The specific research work is as follows:1. According to the grinding heat and heat transfer problems of grinding nickelbase alloy, analysis of the representative cooling and lubricating technologies,summarizes the current research situation about the grinding heat and newcooling lubrication technology at home and abroad. In order to strengthen the capabilityof heat transfer of grinding process, the research topic of this thesis is proposed.2. For grinding heat and thermal dissipation in grinding process, summarizes theexisting cooling lubrication technology and the research status at home and abroad, theoretical analysis of the grinding parameters and grinding heat production, grindingheat source model is established according to the different grinding depth3. For the heat transfer mechanism of grinding interface,"point-line-face" heatsource model of the temperature field is established, the mathematical model ofconvective heat transfer of grinding interface is established according to the differentboundary conditions. Grinding heat distribution of the interface is analyzed and themathematical model for calculating the energy ratio is established.4. Combining with the grinding heat source model, the convective heat transfermodel of temperature field, the modeling and simulation of grinding temperature field ismade with the finite element simulation software and the influence of different coolingand lubricating conditions on the grinding temperature field are studied.5. The plane grinding experiments is made with different cooling and lubricationconditions. Best effect of cooling and lubrication solutions is got determided throughenergy partition coefficient、grinding specific energy、friction coefficient and theworkpiece surface quality. Focus on nanoparticles jet MQL is studied.6. Through the finite element simulation and experimental research. Excellentcooling and lubrication performance of MQL technology by nanoparticles jet is verifiedand the ways of cooling and lubrication to choose the best solution is summed up.