Laser sintered graphene nickel nanocomposites

Abstract

Laser sintered graphene nickel (Gr-Ni) nanocomposites have been successfully fabricated, with uniform dispersion of graphene nanoplatelets in the nickel matrix. Microstructures and composition of the nanocomposites were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Raman spectroscopy. It was demonstrated by EDS maps, XRD patterns and Raman spectrum that graphene nanoplatelets were uniformly integrated in the nickel matrix. TEM images further proved the structure and uniform distribution of graphene in the nanocomposites after laser sintering. HRTEM images revealed the interface between nickel and graphene. High density of dislocation was discovered around the graphene. The strength and elastic modulus of the nanocomposites are significantly improved, as characterized by nanoindentation tests. The hardness tests show that the laser sintered Gr-Ni nanocomposites are around 3-fold higher than that of laser sintered nickel. The strengthening mechanism was also studied theoretically.

Wear and Friction Property of Laser Sintered Graphene Nickel Composite Coating

“…It can be seen form those elements EDS maps, that all the elements were distributed very homogeneously. It was not like the sectional EDS maps in our previous works [14], there, the distribution of those elements were not uniform. This is reasonable, because in the wear and frication experiments, the steel ball rubbed with the samples surface repeatedly.…”

“…The samples were put into a transparent chamber which filled with N 2 gas. The detailed information can be obtained from our previous works [14].…”

“…In order to improve the wear resistance performance of nickel based composite coatings, it is necessary to find new and better reinforcements. It was proved that carbon materials, such as, graphite powder [9,10], CNTs [11,12] and especially graphene [13][14][15], are excellent strengthening materials for many composites and composite coatings.…”

“…So it was reasonable to combining the advantages of graphene and nickel to make the efforts to fabricate graphene nickel composite coatings. It has been reported that graphene was an effective reinforcement for nickel [14,20]. Graphene dispersion is still a common problem, however, for wear resistance coating, it is not a critical problem.…”

Fabricating SiC Nanowire by Vacuum Heating Multilayer Graphene in Silicate Refractory Tube

“…Figure 4 is the XRD test results of SiC nanowires and the remained graphene sheets. It can be seen from the XRD pattern that a peak located at ~26.5°, and this is C (002) peak of multilayer graphene sheets [10]. The others are typical characteristic peaks of SiC.…”