The Effect of Ultrasonic Vibration on Tribological Performance with n-SiO₂ Additives

The tribological performance was investigated with different content of n-SiO₂ additives, with or without ultrasonic vibration conditions, and the lubrication mechanism with ultrasonic vibration and n-SiO₂ additives was discussed. The results show that ultrasonic vibration can improve the lubricating state of friction surface by three ways which are reducing the nano-particles suffered positive pressure, promoting the rolling of nano-particles and increasing the activity of friction surface. The wear scar depth and surface hardness decreased under n-SiO₂ lubrication with ultrasonic vibration, the content of Si element in the wear surface increased, and the lubricating state of friction surface was effectively improved. Within the experimental range, the tribological performance was remarkably affected by ultrasonic vibration when the content of n-SiO₂ additives is 0.5%, and the friction coefficient between friction pair and the wear volume of the 45 steel surfaces was reduced by 12% and 34% respectively.