Microstructural evolution and nanostructure formation in copper during dynamic plastic deformation at cryogenic temperatures

Influence of structural heterogeneity on the structural coarsening during annealing of polycrystalline Ni subjected to dynamic plastic deformation

“…Recently, high strain rate deformation, as has been demonstrated by dynamic plastic deformation (DPD) [3][4][5][6], has drawn increasing interest owing to the significant grain refinement down to nanometer regime as well as the novel final structures that are distinct from the low strain rate deformed counterparts. Taking polycrystalline Ni for consideration, DPD reduces the structural scale down to ~120 nm at a substantially low strain of 2.3, forming typical lamellar structure composed of 70% low angle boundaries.…”

Microstructural characterization of nickel subjected to dynamic plastic deformation

“…Equal channel angular extrusion (ECAE), accumulated roll bonding (ARB), high-pressure torsion (HPT) and several other novel techniques [1,2] have been developed to accumulate very large strains and thus to refine the length scale of the microstructure. In contrast to these techniques of severe plastic deformation, dynamic plastic deformation (DPD) [3,4] utilizes high strain rates (~10 2 −10 3 s -1 ), which has been shown to produce considerable structural refinement at comparatively low strains. For example, the refinement to the nanometer scale has been achieved in cryogenically DPD-processed copper and in a Cu-Al alloy [3][4][5].…”

“…In contrast to these techniques of severe plastic deformation, dynamic plastic deformation (DPD) [3,4] utilizes high strain rates (~10 2 −10 3 s -1 ), which has been shown to produce considerable structural refinement at comparatively low strains. For example, the refinement to the nanometer scale has been achieved in cryogenically DPD-processed copper and in a Cu-Al alloy [3][4][5].…”

“…Two samples were prepared in the form of a cylinder, in which both the height and the diameter of the cylinders were 20 mm. One sample (DPD-sample) was compressed using a dynamic loading technique described in [3,4]. At first the sample was compressed to 8 mm applying a 2-3 mm reduction per pass, after which a ∅10 mm cylinder was machined from the deformed sample to further compress it to a final thickness of 2.1 mm using a 1 mm reduction per pass.…”

Microstructural evolutions and stability of gradient nano-grained copper under tensile tests and subsequent storage

“…The selected-area electron diffraction (SAED) pattern (inset of figure 1b) indicates that the nano-grains are randomly oriented. The majority of the nano-sized grains are separated by indistinct curved or wavy GBs, which are apparently in a non-equilibrium state, as generally observed in nanostructured metals refined by severe plastic deformation [16]. These deformation distorted GBs are characterized by the presence of a high-density of extrinsic GB dislocations and hence of relatively high stress concentrations around GBs.…”