Lubricants Like Mineral Oil or Synthetic Oil Are Used to Reduce the Friction and Wear Between Sliding Parts

Lubricants like mineral oil or synthetic oil are used to reduce the friction and wear between sliding  parts. A lot of additives are used in base oil to enhance the lubricating performance like anti wear, anti rust, anti corrosion, anti friction, extreme pressure, pour point, viscosity modifier and many other types additives. Different composition of additives are used in base oil according to need of  lubricating oil such as ball and sliding bearings, sliding members, ball screw, different types of  gears, friction assemblies, joints, auto mobile engine and other many application where friction and wear to be reduced. Function of these additives in base oil is not to reduce the friction and wear but also to enhance the life of machine and also used for heat dissipatio dissipation n between between mating surfaces, enhance the thermal conductivity of fluid. n the other hand from last few decades there is a lot of other additives are proposed and recommended to use in mineral oil or synthetic oil and grease to increased the performance of  lubricating oil such as micro si!e particle and nano si!e particle. "hile using these particle in base oil the substa substance nce consis consistin ting g of nano nano si!ed si!ed partic particle le attrib attribute ute good good tribol tribologi ogical cal proper propertie tiess as compared to micro si!ed particle.  #ano lubricant  #ano lubricants is a new class of lubricants, in which a nano si!ed particle are disperse in base oil to enhance the tribological properties of lubricating oil. $any researchers has been shown that when some nano si!ed particle are added into base oil, ther tribological properities of lubricating oil improved as other conventional oil. Due to good tribological properties of nano si!e particle in  base oil it attains a great interest of scientist and and engineers. Also Also many researchers researchers showed that the nano si!e particle lubricating oil improved the load carrying capacity heat dissipation, heat transfer  co%efficient co%efficient and thermal conductivity oil. Mechanism of nano sized particle.

&he actual mechanism of nano si!e particle in base oil is still in process but many researcher  hypothesis that it is due to colloidal effect, rolling effects, protection effect and third body effect in  base oil under boundary condition regime. "hen nano si!ed particle are added in base oil it will improved the tribological properties lubricating oil and it was found that various mechanism are effect a' ball bearing effect of particle existed between rubbing surface b' surface polish c' increasing surface hardness Effect of nano particle size

&he effect of nano particle si!e on tribological properties are based on (' the si!e nano particle particle determin determinee their intrinsic intrinsic mechanical mechanical and physicoc physicochemic hemical al properties properties that influence the tribological properties. &he hardness of particle increase while decreasing the si!e of particle. "hile at critical grain si!e below than ()nm become softer and exhibit poor  tribological properties. *' #ano particl particlee based lubricat lubrication ion system system needs to stay stay in contact contact !one during during load and shearin shearing g to protect the rubbing surface. From this point of view the effect of nano particles si!e cab comes into play an important role when we consider the asperities of rubbing surface contact as physical barriers that keep nano particles within the contact !one. +' &hird, &hird, homogeneity homogeneity of nano nano particle particle si!e that that strongly contro controls ls its ability ability to perform perform reliably reliably and smoothly is strongly influenced by collidal effect. t paly an important role of stability and dispersonability of nnao particle in base oil.

The effect of nano particle shape

&he shape of nanoparticles is an very important parameter that may be effect the tribological  behavior of lubricating oil. different shape of particle are used in base oil like spherical, nano sheets and elliptical. &he hape of particle determines the pressure experienced while loading. For  example nano sphere particle experienced good pressure under large load while nano sheets experience bad pressure under high load. The effect of nanostructure

&he internal structure of nano particles can influence the mechanical properties and also their  tribological behavior. For instance the vacancies within the nano materials act as pinning centers inhibiting the dislocation motion, thereby enhancing the mechanical strength within a certain concentration. &hus the presence of a limited amount of atomic vacancies can enhance the tribologival behavior. -ut exssive amount of cavities or vacancies are disadvantges for tribological  behaviour. The effect of surface fictionalization

&he effect of rubbing surface also paly an important role on tribological behavior of nano particle lubrication. "hen the rubbing surfaces are well finished and smooth then the tribological behavior  of nano particle lubrication is good as compared to unsteady and rough rubbing surface. The effect of nano aprticle concentration

&he concentration of nanoparticles within base oil strongly influence the tribological behavior of  lubricating system. n general a optimum concentration of nano particles gives minimum co% efficient of friction and wear loss. f the concentration of nano particle is above or below the optimum ratio its behavior on tribologicsl properties is not good.