Polymer Composites Reinforced by Metallic Architectures and Inserts

Dear Colleagues,

In recent years, research on composite materials has increasingly focused on hybrid polymer–metal systems, in which reinforcement is no longer limited to conventional fibers or dispersed fillers, but instead introduced through discrete, continuous, or architected metallic structures intentionally embedded within a polymer matrix. This emerging class of materials enables performance combinations that are difficult or impossible to achieve using traditional polymer composites, opening new pathways toward enhanced mechanical efficiency and multifunctionality.

Unlike particle-filled polymer composites, polymer composites reinforced by metallic inserts or architectures exploit the geometry, continuity, and connectivity of the metallic phase to tailor load transfer, deformation mechanisms, and functional responses. Metallic meshes, wires, lattices, foams, perforated sheets, or three-dimensional architected networks can be used to introduce directional stiffness, improve impact resistance, enhance energy dissipation, and control electrical and thermal conductivity, while preserving the low density and processability of polymer matrices. In addition, these hybrid systems can enable advanced functionalities such as electromagnetic interference (EMI) shielding, structural health monitoring, sensing, or integrated conductive pathways.

A key aspect governing the performance and reliability of polymer–metal hybrid composites is the metal–polymer interface. Load transfer, damage tolerance, and long-term durability strongly depend on interfacial adhesion mechanisms, including chemical bonding, mechanical interlocking, surface roughness, and geometric anchoring. The role of surface treatments, coatings, and interface engineering becomes particularly critical when continuous or highly architected metallic reinforcements are employed. In this context, the topology and surface morphology of the metallic phase can be deliberately designed to enhance interfacial strength and mitigate failure mechanisms such as debonding or delamination.

From a manufacturing perspective, polymer composites reinforced by metallic structures can be produced through a wide range of conventional and hybrid processing routes. Established techniques include overmolding and injection molding onto metallic inserts, resin casting and impregnation of metallic meshes or foams, resin transfer molding (RTM), vacuum-assisted RTM (VARTM), and co-curing or lamination approaches combining polymer layers and metallic sheets. These methods enable the integration of metallic reinforcements into both thermoplastic and thermosetting matrices, with increasing control over positioning and interface quality.

Beyond conventional manufacturing, additive manufacturing (AM) has emerged as a major technology for the next generation of polymer–metal hybrid composites. Metal additive manufacturing techniques allow the fabrication of complex three-dimensional architectures with controlled porosity, graded density, and tailored connectivity at the mesoscopic scale. Metallic lattices, cellular structures, and topology-optimized reinforcements can be produced using processes such as laser powder bed fusion (LPBF), electron beam melting (EBM), directed energy deposition (DED), or other advanced metal AM routes. These architected metallic structures can subsequently be infiltrated with polymer matrices or combined with polymer processing techniques to form integrated hybrid composites.

At the same time, polymer additive manufacturing and multi-material printing technologies enable new strategies for polymer–metal integration, including direct printing onto metallic inserts, sequential deposition of polymer and metal phases, and hybrid manufacturing workflows combining AM with molding or infiltration processes. Such approaches support the development of function-driven composite materials, in which architecture, material selection, and processing are jointly optimized to achieve targeted mechanical and functional performance.

The potential applications of polymer composites reinforced by metallic structures span a wide range of sectors, including aerospace, automotive, energy, electronics, and biomedical engineering. In these fields, the combination of lightweight polymer matrices with structurally and functionally active metallic architectures offers unique opportunities for damage-tolerant structures, thermally or electrically functional components, and integrated smart systems.

This Special Issue aims to collect experimental, numerical, and theoretical contributions addressing the design, manufacturing, characterization, and modeling of polymer composites reinforced by metallic structures and architected inserts. Particular emphasis is placed on the role of reinforcement architecture, interface behavior, and multifunctionality. Contributions focusing on mechanical performance under static and dynamic loading, impact and fatigue behavior, thermal and electrical transport, electromagnetic response, and durability are especially welcome.

In addition, this Special Issue encourages submissions on multi-scale modeling, finite element simulations, and design-oriented approaches, linking metallic architecture and interfacial features to the macroscopic performance of hybrid composites. By bringing together state-of-the-art research in this rapidly evolving field, this Special Issue seeks to provide a comprehensive overview of current advances, identify open challenges, and highlight future directions for polymer–metal hybrid composites enabled by advanced manufacturing technologies. 

Dr. Cristiano Fragassa
Dr. Ana Pavlovic
Dr. Carlo Santulli
Guest Editors

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• polymer–metal hybrid composites
• metallic architectures in composites
• embedded metal reinforcements
• architected metal inserts
• metal–polymer interface engineering
• load transfer and interfacial adhesion
• multifunctional composite materials
• impact and energy absorption behavior
• hybrid additive manufacturing (polymer–metal)
• topology-driven composite design