A comprehensive experimental study on tribological performance of piston ring-cylinder liner pair

The tribological performance of the piston ring-cylinder liner pair is affected by multiple factors. In this study, the orthogonal test method is used to comprehensively explore the influence of oil dilution, cylinder liner surface coating, and working conditions on the friction and wear of the piston ring-cylinder liner pair. The orthogonal test results show that a certain degree of oil dilution is beneficial to the performance, so the influence of oil dilution is further investigated by using the control variable method. The results show that the liner wear depth decreases first and then increases with the increase of oil dilution. Combined with the scanning electron microscope and energy dispersive X-ray spectroscopy results, it is found that the formation of tribofilm is promoted with a small amount of oil dilution under different working conditions. Meanwhile, a diamond-like carbon (DLC) coating ring and an Fe-based coating cylinder liner can significantly improve the scuffing resistance performance of the piston ring-cylinder liner pair.