The size and the character (low and large angle, special boundaries, tilt and twist boundaries, twins) of the grain boundaries (GBs) in polycrystalline materials influence their strength and their fracture toughness. Recent studies devoted to nanocrystalline (NC) materials have shown a deviation from the Hall-Petch law. Special GBs formed by Σ3 twins in face-centred cubic metals are also known ...

In the last three decades, several severe plastic deformation (SPD) procedures have been developed and applied in materials science to create bulk, ultrafine-grained (UFG) structures. As a consequence of SPD, not only submicron even nanometer grain sizes can be obtained, but also new boundaries with non-equilibrium structures material may formed. Therefore, both strength ductility UFG change si...

The tribological behavior of dual-phase steels have been studied at the macroscopic scale taking macrohardness as main material property to control friction and wear. However, contribution varying properties phase microscopic are yet be fully understood. In this study, microstructures with various grain sizes martensite volume fraction generated. Microhardness ferrite measured by nanoindentatio...

Ultrafine-grained materials display almost no strain hardening, an enhanced rate sensitivity and grain boundary offsets during plastic deformation. It is expected that dislocation climb active in order to enable prompt recovery. The present analysis proposes a deformation mechanism includes these effects follows from the for high temperature sliding. This predicts relationship between rate, flo...

At microscale, the large ratio between mean grain size of the material and specimen dimension cause an increasing influence of single grain forming behaviour on the overall forming process. Thus the forming behaviour of these parts can no longer be regarded as to be homogeneous. This leads to a change in the material behaviour resulting in a large scatter of forming results, e.g. varying cup he...

In this work, we investigated the influence of composition on polycrystalline structure, elastic properties and fracture strength, ZrxSi1-x, NbxSi1-x, MoxSi1-x free-standing thin films that were deposited by magnetron sputtering subsequently annealed at 500 °C. Despite deviations from stoichiometric composition, crystalline structure all films, except for most Zr-rich corresponded to their resp...

Known as having a stress self-accommodation characteristic, the laser cladding shape memory alloy (SMA) coatings have been widely used in material failure repair. Nevertheless, their further development is greatly limited by low microhardness (250 HV0.2) and corrosion resistance. Benefiting from capability of refined grain adjusted microstructure, rare earth oxides play key role improving prope...