Tribological Properties Of Nano-soot Particles As Lubricant Additives

Diesel soot is the product of insufficient combustion which retained in the engine lubricant would have a significant impact on the use of lubricants and expelled to the environment would cause significant air pollution.A large number of previous studies have pointed out that diesel soot could cause serious damage on the mechanical parts,especially inside the engine.In recent years,many studies have shown that it can play a better lubrication and anti-wear effect under certain conditions with the deep study of carbon-based nanoparticles.In addition,surface treatment technology has also been widely concerned in recent years,such as ion nitriding and texture that can significantly improve the friction and wear resistance of materials and reducing material loss.In this study,the tribological and wear properties of diesel soot as lubricating oil additive were studied under the condition of alloy cast iron as flat material under the condition of ball-plate reciprocating motion using UTM-2 friction and wear tester.Firstly,three kinds of diesel soot(Soot A(Loader soot),Soot B(Concrete mixer truck soot),and Soot C(Bulldozer soot))were characterized by AFM,TEM,XRD,FT-IR,Raman,Nano-ZS90 and dispersion experiments.Secondly,the tribological properties and mechanism of friction reduction of diesel soot as lubricating oil additives were investigated by using OM,SEM,Nano Map-D,EDX,Raman,hardness and other equipment.This paper mainly designed three groups of experiments:? The effects of three kinds of diesel soot as PA04 base oil additive(0.01wt%)on the tribological properties of lubricating oil under different temperature(25?,100?,175?)were investigated.? The friction and wear behavior of Soot A with different mass fraction as lubricating oil additive at 100? was systematically investigated.? The friction and wear properties of Soot A as a lubricant(0.01 wt%)on different surface treatment were studied.Through the above research,we get the following conclusions:1:Through the detailed characterization of diesel soot,the results showed that these diesel soot were nanoparticles with a particle size of 10-70 nm and its topography presented spherical or elliptical.Among them,Soot A was smaller and uniform distribution,at the same time which was better crystallinity and more complete.The results of the dispersion experiments show that the Span-80 dispersant can disperse the these diesel soot evenly in the PA04 base oil,and the dispersion effect of Soot A is the best.2:The lubricating oil showed better anti-wear effect after adding 0.01 wt%diesel soot to PA04 base oil.the wear rate respectively decreased by 65%and 80%at 100? and 175?.The mechanism analysis shows that the surface of friction pair can be formed a layer of magnet-graphite composite membrane,which plays the role of protecting the substrate under adding the nano-soot additives lubrication conditions.At the same time nano-soot particles between the existence of rolling,sliding,rolling and sliding compound movement in the process of friction play a ball effect.In addition,diesel soot particles in the friction between the formation of sliding system,so as to achieve anti-wear and anti-wear effect.In addition,diesel soot particles formed sliding system between friction pair,so as to achieve anti-wear and anti-wear effect.3:Concentration experiment results showed that the lubricants shows better wear characteristics after addition of different mass fraction of diesel soot.And when the mass fraction of 0.01 wt%,the anti-wear effect is best.4:The experiment results showed that the samples after treating by different surface treatment methods of ion nitriding,texture(Area rate:19.6%,22.1%,44.2%)and texture-ion nitriding show better anti-wear performance under the condition of PA04 lubrication,and the effect of texture-ion nitriding showed the best wear performance.The wear rate of the samples treated with different surface treatments was reduced under adding the nano-soot additives lubrication conditions compared with PA04 lubrication conditions.5:The particle size,concentration,dispersion stability and surface charge of diesel soot are all important factors that affect the lubricating performance of lubricating oil.Different surface treatment methods have important influence on the tribological properties of the samples.At the same time it will play a more important role in anti-wear with diesel soot.