The Influence of Nanocomposite Carbon additive on Tribological Behavior of Cylinder Liner/Piston Ring

Abstract

Nanocomposite Carbon additive were dispersed at varying concentrations (1, 3, 5wt%) in SN/GF-5 lubricants for automotive engines. Raman spectroscopy is used to characterize the morphology of carbon.The effect of Nanocomposite Carbon additive on the friction and wear properties of the piston ring friction pair is investigated by using UMT friction tester. The tribological mechanism of Nanocomposite Carbon additive is further investigated by scanning electron microscopy, energy dispersive spectrometer and three-dimensional shape spectrometer. The results show that Nanocomposite Carbon additive exhibits excellent antifriction performance at high load and friction coefficient at low load. The effect of the nanocomposite carbon additive is the best when the mass fraction is 3%; however, the nanocomposite carbon additive concentrations is too high, which will lead to increased wear under high load. The nanocomposite carbon particles can smooth the micro-convex of the friction pair surface and reduce the surface roughness. The contact area of the friction pair is significantly increased, and the pressure is significantly reduced. The nano-composite carbon avoids the breakage of the bearing oil film when the metal surface peaks contact each other, ensuring the integrity of the oil film and uniformly carrying a large load.The nanocomposite carbon lubricant additive shown in this study can reduce energy consumption and extend engine life, resulting in significant cost savings.