A Survey on Methods to Improve the Mechanical Strength of Nanostructured Materials

Nanostructured materials, defined by their internal structures being smaller than 100 nanometers, can exist as either single-phase nanocrystalline forms or as multiphase nanocomposites. Interestingly, even nanocrystalline materials can be considered as a type of nanocomposite, where the grains act as the primary phase and the grain boundaries serve as the secondary phase. While traditional composite models can be adapted to describe strengthening in these materials, their unique nanoscale features introduce significant differences compared to conventional strengthening mechanisms. This review explores recent advancements in the theoretical modeling of strengthening mechanisms specifically tailored for nanostructured materials, with a focus on both single-phase nanocrystalline and multiphase nanocomposites. These models are essential for the rational design of new nanostructured materials and other nanoscale composites. For widespread industrial application, these high-strength nanomaterials must also demonstrate good formability, ductility, or other functional attributes to fulfill structural and multifunctional roles. Accordingly, this review also discusses the latest breakthroughs in nanomaterial design that aim to address common trade-offs, such as those between strength and ductility or strength and conductivity. The complex, hierarchical microstructure at the nanoscale presents both challenges and promising avenues for creating next-generation nanomaterials with exceptional performance characteristics