This Brief highlights the search for strain gradients and geometrically necessary dislocations as a possible source of strength for two cases of deformation of materials at small scales: nanoindented single crystal copper and uniaxially compressed single crystal submicron gold pillars.
Read alsoFolk-lore and legends: English
In Vienne, in Dauphiny, is Le puit des fées, or Fairy-well. These fays, it must be confessed, have a strong resemblance to the nymphs of the ancients, who inhabited caves and fountains. Upon a little rock which overlooks the Rhone are three round holes which nature alone has formed, although it seem, at first sight, that art has laboured after…
When crystalline materials are mechanically deformed in small volumes, higher stresses are needed for plastic flow. This has been called the "Smaller is Stronger" phenomenon and has been widely observed. studies suggest that plasticity in one case is indeed controlled by the GNDs (strain gradient hardening), whereas in the other, plasticity is not controlled by strain gradients or sub-structure hardening, but rather by dislocation source starvation, wherein smaller volumes are stronger because fewer sources of dislocations are available (dislocation starvation hardening).