Graphene reinforced aluminum nanocomposites: synthesis, characterization and properties

Novel composites of Al–graphene (0.1–0.3 wt%) have been prepared by powder metallurgical processing. Powder composites were prepared by planetary ball milling route in toluene medium by 5 h of milling under inert atmosphere. Then, optimized high density compacted samples (prepared at 120 MPa) were sintered at 550 °C for 5 h. Various characterization of composites was done by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy, energy-dispersive spectroscopy (EDS), transmission electron microscope, high-resolution transmission electron microscope (HRTEM), selected area diffraction pattern (SAED), micro-Raman spectroscopy, electrical conductivity, and microhardness to obtain an Al–graphene composite with improved microhardness and electrical conductivity. Graphene was found in bi-layer form in the typical sample aluminum–graphene (0.2 wt%) composite. Purity of samples confirmed from EDS analysis showing only peaks of Al and C. XRD, XPS, HRTEM, and SAED studies establish the successful formation of Al and graphene composite. The typical aluminum–graphene (0.2 wt%) sample show significantly higher electrical conductivity (59.2 × 106 S/m) and microhardness (165 ± 08 VHN) values than that of pure aluminum, which shows electrical conductivity and microhardness values of 38.0 × 106 S/m and 65 ± 05 VHN, respectively. The results further advance electrical as well as structural, industrial applications of aluminum.