Timeless Powder Hot Compaction of Nickel-Reinforced Al/(Al2O3-Graphene Nanosheet) Composite for Light Applications Using Hydrazine Reduction Method

This study aims at reducing the aluminum composites time production, exfoliate graphite layers to graphene nano-sheets (GNs) by the mechanical alloy milling, and precipitate a nano-nickel layer by the hydrazine methed on the new hybrid (Al2O3-GNs) particles. Five Al matrix samples containing 20 wt.% (Al2O3-GNs) and different percentages of nickel (5, 10, 15, and 20 wt.%) were prepared by the mixing for 6 hrs. All powder composites were cold pressed then heated in the die at 620 °C for different heating times (15, 5, and 0 min). The zero min time was the best holding time for samples` production. Samples` chemical composition and microstructure were investigated by the x-ray diffraction, SEM, and TEM. The effect of mechanical milling and precipitated nano-Ni on the crystallite size of the Al by the Sherrer method were studied. The actual density of fabricated samples was gradually increased up to 20 wt.% Ni. Good distribution of all constituents was achieved. The hardness was improved by 38.95% at 15 wt.% Ni, and the same sample achieved the highest yield and compression strength (350.3 MPa) and (880.469 MPa), respectively. The 15 wt.% Ni achieved the lowest wear rate. The electrical conductivity decreased gradually by increasing the Ni content up to 10 wt.% then increased for 15 and 20 wt.% nano-Ni. The saturation magnetization and retentivity were improved by increasing the Ni content up to 20 wt.%.