A theoretical model has been developed, which reveals the underlying correlation between the strong extra strain hardening achieved in the nano-grained layers of the grain size gradient structure and the non-uniform deformation of the lateral surface in surface nano-crystallized materials, based on some existing experimental observations and the concept of geometrically necessary dislocations. The proposed model led to the establishment of a simple physical law that can be expressed as H*=A*, where H* and A* are two dimensionless parameters. The former represents the extra strain hardening, while the latter characterizes the non-uniform deformation of the lateral surface. The values of these two parameters can be measured through experiments.
|Pages (from-to)||16 - 21|
|Number of pages||6|
|Journal||Materials Science and Engineering A: Structural Materials: Properties, Microstructure and Processing|
|Issue number||January 2015|
|Publication status||Published - 2015|