Wear resistance of graphene nano-platelets (GNPs) reinforced AlSi10Mg matrix composite prepared by SLM

Abstract

In order to improve the wear resistance of aluminum alloys and expand its applications, the microstructure and tribological properties of nano-graphene reinforced aluminum matrix composites—which were fabricated by selective laser melting (SLM)—were investigated. Experiments were conducted to investigate the effect of slide speeds (0.3–0.9 m/s) and normal loads (10N–30N), which demonstrated the dislocation strengthening and load strengthening resulting from the homogeneous dispersion of graphene nano-platelets (GNPs) enhance the wear resistance of GNPs/AlSi10Mg composites. With the increase of slide speed, the wear rate of composites decreases and the wear regime changes from abrasive wear to delamination wear, which is because the formation of a relatively stable mechanically mixed layer (MML) reduces the contact area between the counterbody material and the wear surface, and the nano-graphene bridges between the subsurface cracks improve the tribological performance. Meanwhile, with the increase of normal load, the predominant wear regime of the reinforced composite is the combination of delamination wear and oxidize wear. And the coefficient of friction (COF) decreases as the slide speed increases, which is because the self-lubricating property of graphene nano-platelets makes it easy to form interlayer sliding and reduce friction effectively.