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The metal matrix composites (MMCs) have been widely used where high specific properties and temperature resistance are required, particularly in aerospace applications. In this work, an ASTM-1100 aluminum alloy in the form of sheets was reinforced with multiwalled carbon nanotubes (MWCNTs) by a novel technique which we have called sandwich technique. Carbon nanotubes (CNTs) are dispersed in a polyvinyl alcohol (PVA) solution; this solution is poured into a container and dried to obtain a reinforced polymer, which is then stretched to obtain a sheet with CNTs aligned in the stretching direction. These composite sheets were stacked with aluminum sheets, and then these stacks were hot compacted in a die using an argon atmosphere to prevent the damage of the CNTs. During this process, most of the polymer evaporates and aluminum diffusion allows obtaining a consolidated matrix with a banded structure of CNTs. The mechanical properties of the composite were measured by tensile and nano-indentation tests, showing increases of up to 100% in the elastic modulus and significant increases in yield and ultimate strength with respect to unreinforced material. Field emission scanning electron microscopy (FESEM) analyses showed a good dispersion of the CNTs within the bands with no evidence of CNTs' damage. No harmful phases were found in the composite after micro X-ray diffraction (XRD) tests. The results showed that the proposed technique is promissory to solve some of the problems in the nano-MMCs manufacturing such as dispersion and alignment of the reinforcing phase.

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