Impact of CuO nanoparticles on the viscosity and vibration damping characteristics of shock absorber oil

This study investigates the potential of copper oxide (CuO) nanoparticles as additives to enhance the viscosity and vibration-damping characteristics of shock absorber oil. Shock absorbers play a critical role in vehicle safety and handling by mitigating vibrations from road irregularities. However, their effectiveness deteriorates over time. To address this, CuO nanoparticles were explored for their ability to improve lubricant performance. Nano-lubricants were prepared by dispersing CuO nanoparticles at varying concentrations of 0.25 wt%, 0.5 wt%, 1 wt%, and 1.5 wt% in a base oil using ultrasonication. The novelty of this research lies in the innovative use of CuO nanoparticles to significantly enhance the viscosity and vibration-damping properties of shock absorber oil. The viscosity of these nano-lubricants increased significantly, with the 1 wt% CuO nano-lubricant achieving a 20% increase at 25 °C compared to the base oil, indicating improved load-carrying capacity and potential friction reduction. Vibration damping performance was evaluated using a dedicated shock absorber test rig. The nano-lubricants exhibited reduced overall vibration acceleration compared to plain oil, with a 15% improvement in damping effectiveness at the optimal CuO concentration. However, the transmissibility ratio, a key damping metric, did not show significant variation, suggesting that traditional shock absorber designs might require modifications to fully leverage the benefits of CuO nanoparticles. These findings demonstrate the potential of CuO nanoparticles to enhance the viscosity and damping characteristics of shock absorber oil, leading to improved performance at lower temperatures.