Tribological Behavior Of Copper,Nickel Nanoparticles And Their Compound System Lubricating Oil Additives

Friction and wear are common problems in nature,and the resulting economic and energy losses are enormous.Due to the inherent structural instability of conventional lubricating oil additives,during high-speed friction,On the one hand,chemical elements?S,P?which are harmful to the environment are generated;on the other hand,these elements will still corrode the instrument under high temperature and high pressure test or application conditions,resulting in a reduction in the life of the instrument and affecting the working conditions.The development of nano-scale lubricant additives began to address such problems.Among the many nano-grade lubricant additives,metal nanoparticles have the advantages of both metal itself and nano-materials,while meeting the requirements of an environmentally friendly society,which makes metal nanoparticles have the potential to become new lubricant additives.Due to its low shear strength,super-stretchability,low melting point and good conductivity,Cu nanoparticles are highly polished and corrosion resistant,with good ductility and high surface activity.Both have the incomparable advantages of traditional lubricant additives,and thus have broad application prospects in the field of tribology.Therefore,our main research contents and results are as follows:?1?Through self-made nano-powder industrial production equipment,Cu and Ni nanoparticles prepared by macro-preparation technology have the advantages of good dispersibility,small size,uniform particle size distribution,and core-shell structure,which meet the experimental requirements as a lubricant additive.?2?The Cu nanoparticles are added as a lubricating oil additive to the PAO6 base oil to form a lubricating oil colloid system.The lubricating oil anti-wear performance measurement method?four-ball method?was used to determine the optimal addition ratio of Cu nanoparticles to 0.1wt.%,and the lubrication mechanism of metal nanoparticles as a lubricant additive was explained as the"micro-bearing"and the deposition mechanism of the deposited film..The compound effect study found that the Cu nanoparticle lubricating oil additive has better antiwear and antifriction effect with the common compatibilizer oleic acid?OA?,and the anti-oxidant anti-corrosion agent dialkyl dithiophosphate?ZDDP?.The effect of the compounding is not good.?3?The Ni nanoparticles were added as a lubricating oil additive to the PAO6base oil to form a lubricating oil colloid system.The lubricating oil anti-wear performance measurement method?four-ball method?was used to determine the optimal addition ratio of Ni nanoparticles to 0.5wt.%.The compounding effect study found that the Ni nanoparticle lubricating oil additive was compounded with the commonly used compatibilizer oleic acid?OA?.It has better anti-wear and anti-friction effect,and has a poor compounding effect with the anti-oxidant anti-corrosion agent dialkyl dithiophosphate?ZDDP?.?4?The Cu and Ni nanoparticles were blended into a lubricating oil colloid system of different mass fractions,and the orthogonal experiment was carried out by using the lubricating oil anti-wear performance measuring method?four-ball method?.The study found that the optimal total addition amount is 0.5wt.%,and the optimum ratio of Cu and Ni nanoparticles is wt_Cu%:wt_Ni%=60%:40%.Furthermore,it was found that the ternary compounding of Cu and Ni nanoparticle compounding system and OA has better antiwear and antifriction effect.?5?Adding Cu nanoparticles to the CD⁺grade tank oil according to the optimal addition ratio of 0.1wt.%,and improving the CD⁺grade tank oil,using the lubricating oil anti-wear performance measurement method and the lubricant bearing capacity test method for friction The experimental results show that the friction coefficient and the wear spot diameter of the CD⁺+Cu system after adding the Cu nanoparticle lubricating oil additive are 29.12%and 17.63%,respectively,compared with the CD⁺grade tank oil.0.1wt.%was added to CF-4,CH-4,CJ-4 full formula oil,and the CD⁺grade tank oil was replaced by the long-run and extreme pressure performance test by the four-ball test machine.The tribological performance test under different loads showed that the CF-4+Cu full formula lubricating oil system showed better replacement of CD⁺grade tank oil.