Mechanical behavior of nanostructured metals

Nanostructured materials exhibit unique mechanical behaviors and properties that are different from those of their coarse-grained counterparts. Nanostructured metals synthesized by nanopowder consolidation often contain flaws such as porosity, gas bubbles, and unconsolidated oxide boundaries between the original nanoparticles. These flaws make nanostructured metals brittle without being able to accommodate much plastic strain. On the other hand, nanostructured metals processed by severe plastic deformation techniques or electrodeposition can avoid the abovementioned flaws and often exhibit high strength and high plasticity under some deformation modes. However, their ductility, which can be defined as tensile plasticity, is often extremely low because of their low strain hardening capability. The key to improving their ductility is to improve their capability for sustained strain hardening.