Impact of Graphene and Hot-Rolling on the Microstructure and Mechanical Properties of Aluminum Matrix Nano-Composite

Abstract

Due to the low density of aluminum, it has become the first choice of materials for designers. Aluminum is also characterized by high specific strength. It still suffers from inferior mechanical properties, such as its high ductility, limiting its use in industry in the pure state. In this research, trials to improve the mechanical properties of aluminum by maintaining its low density. It was the first choice among materials to improve aluminum's mechanical and physical properties. Because of the importance of graphene resulting from its low density and unique properties as a newly discovered material, researchers tried to study its effect in various fields. Using the method of powder metallurgy followed by the hot rolling as a secondary process, aluminum composites reinforced with 10% copper, 2.5% alumina, and different weight ratios of graphene up to 1.5% were manufactured. The components were mixed for 45 hours in the presence of 5% hexane as a PCA by mechanical alloy milling using 12 mm balls and a 10:1 ball to powder ratio. The appropriate pressure, temperature, and sintering time were determined for the manufacture by the powder metallurgy method. The results by powder metallurgy method showed a general improvement in the microstructure and physicomechanical properties up to 1% graphene. Still, the results deteriorated at 1.5% due to the presence of some accumulations of graphene. By conducting the hot rolling process, all results exceeded their counterparts by the powder metallurgy method and improved up to 1.5%. In general, the microstructure in both cases before and after the hot rolling was ideal.