Wear and performance analysis of a 4-stroke diesel engine employing nanolubricants

In the present study, the performance of a 4-stroke diesel engine was experimentally evaluated upon adding Al2O3 or SiO2 nanoparticles to the engine oil (SAE15W40). The viscosity and density of the resulting nanolubricants were determined while varying both the nanoparticle volume fraction and the temperature. Field emission scanning electron microscopy (FE-SEM) showed that the nanoparticles had a spherical morphology and dynamic light scattering analysis determined some aggregation of the nanoparticles in the engine oil. A pin-on-disc test apparatus was used for friction and wear analysis in the presence of the nanolubricants. Examination of wear scars by FE-SEM and energy dispersive spectroscopy found evidence of ball bearing and surface polishing effects, which were responsible for improvements in the tribological properties of the oil. The performance of these nanolubricants in a 4 stroke diesel engine test rig was assessed, and the greatest improvements in the tribological behavior and engine performance were observed when employing 0.3 vol% Al2O3. (C) 2017 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.