Effect of Sample Preparation on the Microstructural Evaluation of Al–GNPs Nanocomposites

Metallography is a key characterization method which can be affected by different variables. In aluminum–graphene nanoplatelet nanocomposites, mechanical interlocking is the main interfacial bonding. During the standard polishing, graphene nanoplatelets are removed leaving microvoids, and consequently in the microstructure of samples after sintering, two types of microvoids are revealed: one corresponding to the lack of sintering and another to the location of graphene which is removed during the polishing step. Thus, in this work a different polishing route is recommended to avoid the formation of the polishing related microvoids.