Theoretical Analysis And Experimental Rasearch Of Grinding Temperature And Convective Heat Transfer Mechanism On Nanofluids Minimal Quantities Of Lubrication

A series of studies of vegetable oil minimum quantity lubrication(MQL)grinding is also less.And most of existing researches focused on influences of nanofluid parameters(e.g.nanoparticle type,nanofluid concentration and base fluid type),jet parameters(e.g.nozzle distance,nozzle angle and air pressure)and grinding parameters(e.g.feed speed,grinding depth,circular velocity of the abrasive wheel and workpiece type)on grinding force,grinding temperature and workpiece quality.They didn't give relatively reasonable explanations to experimental phenomena and disclose the scientific essence of MQL from physical properties of nanofluids(e.g.viscosity and surface tension).A progressive system research has been conducted on vegetable oil-based nanofluids.And cooling heat transfer mechanism has been analyzed and discussed on nanofluids MQL grinding.This article main research content is as follows:(1)Based on the grinding mechanism,the main grinding parameters in grinding process,such as grinding force,grinding temperature,the energy ratio coefficient transferred into workpiece were analyzed.Numerical simulation model was established based on finite difference method combining with nanofluids MQL grinding.And the numerical analysis model was carried out on the grinding temperature.(2)Experiment research on pure vegetable oil MQL grinding was conducted.The different kinds of vegetable oils,including castor oil,palm oil,soybean oil,corn oil,peanut oil,sunflower oil and rapeseed oil were used as base oil MQL grinding high temperature nickel base alloy.Grinding temperature and the energy ratio coefficient were theoretically analyzed,and the experimental results were analyzed from the own characteristic of vegetable oil(viscosity,fatty acid type and molecular structure),choosing the better vegetable oil with nice cooling heat transfer effect.(3)Experiment of high temperature nickel base alloy with different kinds of nanofluids was conducted.Nanofluids were prepared by vegetable oil with good cooling heat transfer effect and different nanoparticles,including Al2O3,PCD,MoS2,CNT,ZrO2,SiO2.The different heat transfer mechanism of different nanofluids on thegrinding process was analyzed,and the nanoparticle with better heat transfer performance was chose.(4)Cooling heat transfer mechanism of MQL grinding of different concentration nanofluids was studied.The vegetable oil and nanoparticle,which were chose by above studies,were prepared into different volume concentration nanofluid.The effect of the nanofluid physical properties(thermal conductivity,viscosity and contact Angle)on grinding force,grinding temperature and the energy ratio coefficient transferred into workpiece was analyzed.And the best nanofluid concentration with good cooling and lubrication was chose.(5)Heat transfer performance of nanofluid with different concentration MQL grinding different workpiece materials(45 steel,nickel base alloy and ductile iron)was studied.The grinding forces and grinding temperature were analyzed combined with the numerical simulation analysis of the three typical workpiece material using nanofluids with better cooling and lubrication effect.And the state of nanofluids was also discussed in the grinding zone and heat transfer mechanism.