Graphene Reinforced Aluminum Matrix Composites Produced by Powder Metallurgy; Microstructure, Thermophysical And Mechanical Properties

Aluminum matrix nanocomposites reinforced by different graphene nanoplatelets content were produced by a novel wet mixing followed by conventional powder metallurgy. The microstructure, thermal conductivity, thermal expansion coefficient and compressive strength of the nanocomposites were investigated. Microstructural evaluations show that at lower graphene contents a uniform dispersion of GNPs can be achieved while at the higher GNPs content they start to form some agglomerates. Outcomes of the mechanical properties evaluation indicate that the addition of low GNPs content improve the hardness and compressive strength of the composite, while the effect of high GNPs content is opposite. Furthermore, the thermal conductivity of composites decreases as a function of GNPs content. It is also found that the coefficient of thermal expansion of composites is reduced by the introduction of GNPs. The agglomeration of GNPs is exacerbated as a function of graphene content, which is the main reason for the deterioration in most of the properties.