Article ID Journal Published Year Pages File Type
1524654 Materials Chemistry and Physics 2011 8 Pages PDF
Abstract

The multifunctional diversities existing in nature provide clues to speculate the structure–property–function relationships. A hierarchically structured steel is designed by using principles derived from nature and fabricated in situ by a one-step method of surface mechanical attrition treatment (SMAT). The microstructure of the processed steel is characterized by multilayered structure with hard nanocrystalline surface and compliant inner-layer, in particular with a smooth mechanical gradient induced by dual-phase constituents and multiscale grain size distribution. The hierarchically structured steel exhibits simultaneously high stiff, strong and large ductility, which originate from the joint deformation mechanisms of distinct reinforcing layers. The four layers present their own unique deformation mechanisms, including second-phase hardening, transformation induced plasticity and twin strengthening. The unique spatial form of gradation can release stress concentration and improve energy-dissipation leading to exceptional mechanical properties compared with the uniform materials.

Related Topics
Physical Sciences and Engineering Materials Science Electronic, Optical and Magnetic Materials
Authors
, , , , ,