It has been known for more than half a century that crystals can be made stronger by introducing defects into them, i.e., by strain-hardening. As the number of defects increases, their movement and multiplication is impeded, thus strengthening the material. In the present work we show hardening by dislocation starvation, a fundamentally different strengthening mechanism based on the elimination...

Grain refinement can make conventional metals several times stronger, but this comes at dramatic loss of ductility. Here we report a heterogeneous lamella structure in Ti produced by asymmetric rolling and partial recrystallization that can produce an unprecedented property combination: as strong as ultrafine-grained metal and at the same time as ductile as conventional coarse-grained metal. It...

The complete stress field, including the microstress, the moment-stress, and the line forces are derived for the pure bending of a rigid-plastic beam of rectangular cross-section in the model of strain-gradient plasticity. The workless spherical parts of the microstress and the moment-stress tensors are incorporated in the analysis. Their determination is shown to be of importance for the fulfi...

It is well known that damage evolution models requires a length to avoid spurious localization. We gather these type of models under the name “non-local damage models”. In fact, non-locality is strictly needed only when the stress-strain curve starts to have a negative slope. Before this point, local models may be used. For instance, when damage exhibits some hardening, the stress-strain curve ...

Experiments were carried out in which the dependence of the fractional softening on temperature, time and strain rate was determined in a 304H stainless steel. Three prestrain ranges were identified pertaining to three different post-deformation softening behaviors: 1) prestraining to below the DRX critical strain: strongly strain dependent softening by SRX alone with softening kinetics control...

Ni 3Al, an L12 structure intermetallic crystal, is the basic composition of the y' precipitates in nickel-based superalloys and is a major strengthening mechanism contributing to the superalloys' outstanding high-temperature mechanical properties. Many L12-structure crystals present unusual macroscopic mechanical properties, including the anomalous temperature-dependence of yield strength and s...