Architecting advanced aluminum matrix composites for enhanced performance

In critical aerospace structures such as aircraft ventral fins, satellite frames, and landing-gear supports, automotive brake rotors, pistons, and cylinder liners, as well as high-power electronic heat sinks and thermal-management systems for electric vehicles, aluminum matrix composites (AMCs) deliver the combination of low density, high specific strength, and superior thermal–electrical performance demanded by next-generation engineering applications. This manuscript provides a critical and up-to-date review on the evolution of AMCs from traditional monotype designs, using single reinforcements, to advanced hybrid architectures that combine multiple reinforcements. Particular emphasis is placed on synergistic graphene-carbon nanotube (CNT) reinforcement systems designed to overcome common limitations of monotype composites, such as particle agglomeration, weak interfacial bonding, and property trade-offs. The review systematically examines key fabrication methods, including ultrasonic additive manufacturing (UAM), spark plasma sintering (SPS), and hybrid processing techniques, highlighting their roles in achieving improved dispersion and controlled reinforcement alignment. Hybrid architectures, particularly interconnected graphene-CNT networks, demonstrate significant improvements in mechanical strength, hardness, thermal conductivity, and electrical conductivity compared to conventional monotype systems. The review discusses critical challenges related to processing, scalability, production costs, and environmental considerations associated with nanomaterial reinforcements. Finally, future research directions are outlined with a focus on cost-effective manufacturing strategies, improved interface engineering, and sustainable processing approaches. This review provides a comprehensive framework for researchers and engineers to design and develop high-performance hybrid AMCs for next-generation engineering applications.