Experimental Study Of MoS₂/WS₂ Hybrid Nanofluidic Micro-lubrication Grinding

Grinding is a machining method mainly used to produce finished parts with the required shape,size and precision,and it plays an extremely important role in the production or manufacturing process of products in the manufacturing industry.As the application of difficult-to-machine materials such as ceramics and super alloys becomes more and more widespread,the problems of damage,cracks,fractures and severe tool wear that occur in the grinding process for these materials have not been solved,and the traditional cooling and lubrication methods are ineffective,the surface quality obtained is low,and the large amount of grinding fluid used causes serious pollution to the environment,which does not meet the requirements of today's green manufacturing era.Based on the above problem,we propose a method to apply MOS₂/WS₂hybrid nanofluid microlubrication to the grinding of difficult-to-machine materials.The environmentally friendly vegetable oil is used as the base oil,and nanoparticles are added to enhance the thermal conductivity of the lubricating fluid and the convective heat transfer capability and lubrication characteristics of the grinding area.The specific research work is as follows.1.The mechanism related to nano-fluid micro-lubrication grinding processing was studied,the mechanism of action of abrasive grains in removing material from the workpiece surface during grinding was analyzed,and various evaluation parameters of lubrication performance were established;the mathematical model of microscopic grinding force was established,the normal sliding friction force and tangential sliding friction force were calculated,and it was applied to the calculation of microscopic friction coefficient to further express the lubrication effect in the grinding area.2.Three dispersion methods,mechanical stirring,mechanical stirring+surfactant and mechanical stirring+surfactant+ultrasonic vibration,and the effect of surfactant on the suspension stability of nanofluids were investigated;the relationship between the suspension stability of nanofluids and the mass of surfactant and nanoparticles,and the effect of ultrasonic vibration time on the stability of nanofluids were analyzed.3.Grinding experiments with different mass fractions of nano-lubricants were conducted on a difficult-to-process material,high-temperature alloy,to investigate the cooling and lubricating properties of nanofluids with different mass fractions under the same grinding parameters.Comparative grinding experiments were conducted under four working conditions(dry grinding,casting,micro-lubrication and nanoparticle jet micro-lubrication)to fully demonstrate the superiority of nanofluid over the other three lubrication conditions;the effect of the mass ratio of the two particles in the mixed nanofluid on the grinding performance was further investigated,and the grinding performance parameters such as grinding force,specific grinding energy,surface roughness(Ra,RSm and coefficient of variation)were investigated The mechanism of the interaction between MOS₂/WS₂hybrid nanofluid.4.Different mass fractions of nanoparticles were added to palm oil to analyze the variation trend of lubricant viscosity with the mass fraction of nanoparticles;combined with the particle mass ratio of the best lubrication effect of mixed nanofluids,the effect of nanoparticle concentration on grinding performance as well as fluid viscosity and contact angle was further investigated,and six different fluids with mass fractions from 2%to 12%were designed to investigate their different grinding lubrication performance and contact angle variation patterns.