Experimental Study On Tribology Property Of Nanometer WS₂ Lubrication Oil And Grinding At Minimum Quantity Cooling Lubrication?MQCL?

Grinding process is a kind of process method to obtain high surface geometry precision and quality.It is also the main processing method of high temperature resistant materials,non-metallic new materials and high hardness alloys.In the process of grinding of abrasive mostly negative rake angle processing,the grinding heat is more than other forms of several common processing,detracting the service life of the grinding tool,to reduce the surface precision of workpiece,on the other hand,grinding is the continuous process of repeated scraping and micro-cutting on the surface of the workpiece,affecting the workpiece surface quality.Pouring grinding process is often used in grinding process to solve the damage problem of grinding heat and machining surface.However,its large amount of grinding oil,environmental pollution and high waste disposal cost cannot meet the requirements of modern green processing.Dry grinding process and minimum quantity lubrication?MQL?grinding process can meet the requirements of low cost and pollution,but its cooling and lubricating ability is unsatisfactory.In recent years,a new cooling and lubrication technology,minimum quantity cooling lubrication?MQCL?grinding process have been able to solve the problem of heat transfer in the grinding area.Nevertheless,its lubricating ability needs to be improved.Because of its small particle size,large surface area and easy diffusion,nanoparticles can improve the wear resistance and bearing capacity of lubrication oil,and the nanoparticles with high heat exchange capacity can enhance the cooling capacity.In this paper,WS₂ nanoparticles,a new green and environmental nanomaterials with high anti-wear ability and heat transfer capability,is used as additive for cryogenic cutting oil CTY-B,researching dispersion stability and tribological properties of nanoparticles as additive in cryogenic cutting lubrication oil.A new type of grinding cooling and lubrication method combining cryogenic cutting oil containing WS₂ nanoparticles with MQCL grinding process is proposed,and the single variable grinding test was carried out under four different cooling conditions.The main research work is as follows:To analyze the methods of the preparation of the lubrication oil with WS₂ nanoparticles as additive,using the two-step method and mixing the mechanical agitation,the thermostat,and the ultrasonic vibration to prepare,the effects of Span-80,sodium dodecyl benzene sulfonate and PEG-6000 as surfactant on the dispersion stability of oil were investigated,nano-tungsten disulfide lubrication oil containing different mass fraction were prepared.A HRS-2M high speed reciprocating tribotester was performed to evaluate the tribological property of cryogenic cutting oil with different amount of nano-tungsten disulfide,the best content of WS₂ nanoparticles as additives in cryogenic cutting oil is determined.The micromorphology and element composition of worn surface were characterized by using scanning electron microscopy and energy dispersive spectrometer,the anti-wear,anti-friction mechanism and self-healing properties of WS₂ nanoparticles were analyzed.This thesis investigated the variation trend of grinding force and specific grinding energy with grinding parameters under different cooling and lubricating condition.Under the same grinding parameters,different cooling and lubricating condition,the grinding temperature and the surface quality were compared.To verifying the excellent cooling ability and lubrication effect of cryogenic cutting oil with WS₂ nanoparticles combined with MQCL grinding process.The anti-wear mechanism of WS₂ nanoparticles in grinding process was researched by using the energy spectrometer on the surface of grindingNano-Cu was used as compound additive of cryogenic cutting oil containing WS₂ nanoparticles.The tribological properties of compound WS₂/Cu nanoparticles lubricating oil were investigated by changing the amount of nano-Cu,the synergistic effect of WS₂/Cu nanoparticles,wear resistance and friction reduction,the mechanism of repair performance were discussed.