An Investigation of the Effect of Addition of Nanoparticles on the Properties of Lubricating Oil

Lubrication is essential to reduce friction and wear in mechanical parts thus minimizing the associated dissipative energy loss. Viscosity is the most important property of lubricating oil, which accounts for its flow resistance. Other important properties of lubricating oil include the flash point and the fire point, which are related to oil storage and handling. The present work is an attempt to study the effect of inclusion of nanoparticles on the kinematic viscosity and the flash point of lubricating oil. Copper oxide and aluminum oxide nanoparticles were suspended in two stroke Servo SAE 20 W-40 lubricating oil using standard ultrasonic agitation process, and the properties of the resulting suspension studied. The effects of the volume fraction of nanoparticles (dosing level varying from 0.02 to 0.2 percentage by volume) on the kinematic viscosity and flash point of the suspension were studied, treating the temperature as a parameter in the range 30°C to 65 °C. An initial increase and subsequent decrease was noticed in the kinematic viscosity as well as the flash point, with an increase in the volume fraction of the nanoparticles. Possible reasons for this behavior were understood to be the increase in density, and the agglomeration of nanoparticles as the dosing level increases.