High density nano-scale twins in Cu induced by dynamic plastic deformation

Microstructural characterization of nickel subjected to dynamic plastic deformation

“…These values are much greater than those in Cu cryogenically deformed to a similar strain, where a fine average boundary spacing (40 nm) was achieved due to a very high frequency of twin boundaries [3]. The boundary spacings in Ni are however considerably smaller compared to those achieved in Al even after cryogenic DPD [6].…”

“…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.…”

Effect of the stacking fault energy on the mechanical properties of pure Cu and Cu-Al alloys subjected to severe plastic deformation

“…In addition, the grain refinement to the nano regime may occur by fragmentation of nanoscale twins [9,10]. It was shown that the dynamic plastic deformation at low temperatures in alloys with a low SFE promotes the formation of high density of nanoscale twins [11,12].…”