Fabrication And Properties Of The Nckel Matrix Graphene Composites

Graphene possesses excellent mechanical properties, thermal andelectrical characteristics. Using graphene as second-phase particles in themetal-matrix composites may provide the new material innovativefunctions.Graphene oxide (GO) single-layer nanosheets were reduced tographene under the cathode condition with the coelectrodeposition of nickelions, which fabricated the Ni matrix composites containing homogeneouslydispersed graphene sheets. After discussing the influence of theconcentration of GO and current density to the graphene content in thecomposites, we fabricated0.12wt%Ni-graphene composites. Atom forcemicroscopy (AFM), Raman spectroscopy, scanning electron spectroscopy(SEM) and transmission electron spectroscopy (TEM) were used tocharacterize the graphene of the composites. The results of X-ray diffraction(XRD) and high-resolution TEM (HRTEM) showed that the reducedgraphene sheets changed the preferential growth orientation of nickelparticles from the original (200) to (111).Then we did some exploratory researches on the properties of theNi-graphene composites. It has been discovered that the thermalconductivity of0.12wt%graphene composites increased15%and itselectrical conductivity raised34%. Nanoindentation experiments showedthe composites have a hardness of5.69GPa and an elastic modulus of190.57GPa. Comparing to a hardness of1.81GPa and an elastic modulus of160.39GPa exhibited by the pure Ni electrodeposits. Extension testsdemonstrated the yield strength of0.12wt%graphene composites improved2.4times and its rupture strength enhanced2.8times. Moreover, we studied the influences of heat treatments to the pure Nielectrodeposits and Ni-graphene composites. The composites acquired thebest mechanical performances after300℃heat treatment.