Abstract: Nano-structured metals and their alloys possess superior mechanical properties.
The defects inside or on the surfaces of the nano-structured metals, including grain
boundaries, dislocations, twin boundaries, voids, cracks, the second phases, etc., can influence
the materials strength and toughness significantly through their nucleation, evolution
and interactions. This review article surveys the advances in microstructure characterization
and mechanical testing, as well as computations and simulations on strengthening and
toughening mechanisms of several novel nano-structured metals. It is also proposed that the
comprehensive investigation is necessary on nano-structured metals to obtain the specific
mechanical behaviors and primary deformation mechanisms at atomic scales.