Ganapathy, S., Viswanathan, K., Raju, S., and Appancheal, A., "Comparative Study of Different Nanolubricants for Automotive Applications," SAE Technical Paper 2016-01-0486, 2016, doi:10.4271/2016-01-0486.
The intervention of Nanotechnology in the field of lubricants have found path to several new lubricants for high temperature applications. Nanolubricants are the nanoparticles suspended in base lubricants, are being developed to increase the performance of machine components at high temperatures, which reduces friction and wear in sliding contact encountered in many heat engines and industrial applications. An attempt has been made to study the effect of the Yttria stabilized Zirconia (YSZ), Calcia stabilized Zirconia(CSZ), and Aluminium Oxide nanoparticles in the lube oil base stock. The nanoparticles were synthesized using Ball mill and the nanoparticles were found to be in the range of 50 to 90 nm. The 40 hrs milled nanoparticles are characterized by Scanning Electron Microscope and Transmission Electron Microscope, and the chemical composition of these nanoparticles are characterized by Energy Dispersive X-ray Analysis which conforms the presence of YSZ, CSZ, and Aluminium Oxide nanoparticles. The impact of temperature in nanolubricants is analyzed using Thermogravimetric analysis and Differential Scanning Calorimeter tests. From TG-DTA analysis it is observed that, Al2O3 nanoparticles has residue 85.53%, YSZ nanoparticles has residue 94.32%, and CSZ nanoparticles has residue 93.98% under thermal conditions upto 1000°C. This study illustrates the nanoparticles are heat stable under different thermal conditions, undergoes small degradation in high temperature. The friction co-efficient and wear rate of the different nanolubricants are found out with the Ball-on-disc tribometer. The surface morphology of YSZ nanolubricants are observed to be smooth and small wear rate; which is due to the formation and effective spreading of the nanoparticles, which are the important factors contributing to the reduction of friction co-efficient and wear rate. The important study of thermal properties such as Viscosity, Viscosity Index, thermal conductivity, Flash point, Fire point and Pour point are carried out and improvement in the thermal properties have proved that these nanolubricants are found to be effective at high temperature applications.