Die versetzungsanordnung in plastisch verformten kupfer-vielkristallen

On the Orientation Changes during Plastic Deformation of Individual Crystallites in Polycrystalline Aggregates

“…Hence the Taylor theory proved as a good approximation to the deformational behaviour of the whole polycrystalline aggregate. I n a recent investigation on copper polycrystals it was found that multiple slip takes place for deformations up to 1 yo [9], which is in good agreement with the present results. Fig.…”

Deformation defects in nanocrystalline nickel

“…This twin was likely heterogeneously formed via the emission of Shockley partial dislocations from GBs, much like the fivefold twin reported in nc Cu after severe deformation [22]. The formation mechanism of multifold deformation twins is likely due to sequential twinning [34]. Deformation twins observed in nc Ni grains indicates the operation of PDMPs.…”

“…They may also form in the way suggested by MD simulations [3]: after a single partial dislocation is nucleated, the nucleation of a trailing partial dislocation follows on the same slip plane, and as such a full dislocation will be formed when the trailing partial catches up with the leading one. The dislocation processes in nc grains are thermally activated, as revealed by the stronger-than-normal temperature/ strain rate dependence of the flow stresses [28][29][30][34][35][36]. At low deformation temperature, the relaxation/ adjustment in the grains and GBs is depressed, and the activation of dislocations would then rely largely on the local stress intensity (depending on the applied stresses, internal stresses, and the stress field of the leading partial).…”

Environmental Cracking Of Metals

“…On the contrary, an extensive series of investigations carried out from the 1960s through the 1980s by Swann, 63 Essmann et a/., 64 85 showed the absence of any debris layer. Solution composition within a crack, as well as within a pit or crevice, is considerably different from that in the bulk solution at the crack mouth, because of restricted mass transport.…”