Discovery of New Strengthening Law in Nanocomposite Reinforced by Ceramic Nanoarchitected Materials

Engineers have long sought to utilize the exceptional mechanical properties achieved by size effect at the macroscopic level, as the strengthening effect derived from size is exclusive to the nanoscale realm. In this work, we present a novel approach to harness the size-induced strengthening effect and apply it on a macroscopic scale in a three-dimensional (3D) metal/ceramic/metal (MCM) nanocomposite. 3D Ni matrix nanocomposites embedding nanoscale Al₂O₃ nanoarchitectures were produced in a large area (~1 inch) using Proximity-field nanopatterning (PnP) and material conversion techniques. Ceramic thin-shell nanoarchitected materials (t < 100 nm), utilized by a reinforcement of metal nanocomposite, perfectly separate 1^st and 2^nd metal layers. 1^st and 2^nd metals are densely infiltrated in and out of the ceramic nanoarchitected materials without defects. The 3D Ni/Al₂O₃/Ni nanocomposite exhibits a significantly higher compressive strength, surpassing the upper bounds predicted by conventional rule of mixture by approximately 30%. This remarkable strength is attributed to the extrinsic size effect of the ceramic nanoarchitected materials. By integrating the size-induced strengthening of ceramics into the traditional strengthening models of composites, a new strengthening model is derived and experimentally validated using the 3D Ni/Al₂O₃/Ni nanocomposite system. The utilization of size-induced strengthening in nanomaterials allows the 3D MCM nanocomposite system to offer a novel approach for enhancing the mechanical properties of bulk materials.