Fabricating graphene nanoplatelets/nickel composites of balanced strength and ductility

Abstract

In this work, a feasible strategy to fabricate graphene nanoplatelets (GNP) reinforced nickel (Ni) matrix composites is developed, in which the in-situ exfoliation and dispersion of GNP are synchronized. This strategy consists of preparing composite powders by three dimensional (3D) vibration milling Ni powders with graphite bulks and consolidation process by spark plasma sintering (SPS). Characterization results show that GNPs are stripped from the graphite bulk and homogeneously distributed on Ni powders surfaces. Compared with pure Ni, the 0.1 wt % GNP/Ni composites demonstrate a yield strength of 338 MPa and ultimate tensile strength of 593 MPa, achieving improvement by 29.5% and 24.8% respectively, and preserve good ductility simultaneously. Due to the grain refinement and efficient load transfer, the obtained GNP/Ni composites exhibit superior strengthening efficiency. This strategy can be disseminated to simple and economical preparation of other metal matrix composites reinforced with GNP.