Production and characterization of Al composites reinforced with Ni coated graphen nanoplates

In this study, the effects of nickel-coated graphene addition on the physical and mechanical properties of aluminum composites were examined. The work primarily started by coating graphene nanoplates (GNP) with nickel. Five different chemical processes were followed for this process. These include cleaning GNP particles, increasing surface roughness, activating the surfaces and applying the coating solution. After the chemical coating processes were completed, Al and Ni-GNP (0; 0.8; 1.2 and 2 wt%) powders were turned into bulk samples by applying traditional powder metallurgy procedures. Beforehand, the starting powders were mixed in a ball mixer at a rotation speed of 300 rpm for four hours. Stearic acid at a rate of 0.3% by weight was used as a process control agent during the mixing. To prevent cold welding and prevent the structure of graphene from deteriorating, the ball milling was operated for 20 minutes with a 10-minute rest in each cycle. After mixing, the powder samples were cold pressed under 600 MPa pressure. Bulk samples with green strength were subsequently subjected to sintering under argon atmosphere at 630°C. Subsequently, Vickers microhardness test and compression test were applied to determine the mechanical properties of the produced composite materials. Experimental microhardness results were analyzed using Meyer's law, proportional sample resistance model, elastic-plastic deformation model and Hays Kendall (HK) approach. Thus, the Hays–Kendall approach was determined as the most appropriate approach model. With the increasing Ni-GNP ratio, a 7% increase in compressive strength was achieved.