Severe plastic deformation is a technical method to produce functional material with special properties such as high strength and specific physical properties. Selection of an efficient severe plastic deformation for grain refinement is a challenging field of study and using a modeling technique to predict the refinement efficiency has gained a lot of attentions. A comparative study was carried...

The plastic deformation behavior was investigated by using nanoindentation in a magneto-sputtered nanocrystalline (nc) Cu film with an average grain size of 14 nm. The determined critical shear stress to initiate plasticity in the nc-Cu sample (about 8.3 GPa) is identical to that for nucleation of lattice dislocations in an annealed coarse-grained Cu (8.5 GPa), and both values are close to the ...

A coupling between phase transformation and viscoplasticity is observed in HTSMAs during actuation. The dislocations generated retained phases accumulated are responsible for the coupling. It results functional fatigue, which reflected as an alteration properties of alloy, increase irrecoverable deformations. objective present study was to develop a theoretical framework account interactions si...

It is planned that doped copper overpacks will be utilized in the spent nuclear fuel repositories Finland and Sweden. The assessment of long-term integrity material a matter importance. Grain structure variations, segregation any possible manufacturing defects microstructure are relevant terms susceptibility to creep damage from loading evolution imposed by its operating environment. This work ...

Abstract. In additive manufacturing processes, the resulting products might have highly anisotropic granular morphologies due to complex thermal history. The most commonly observed morphology is columnar structure. of grains accompanied by orientation alignment leading plastic anisotropy. It has been shown in a recent study through local crystal plasticity calculations that evolution does not i...

A review is given of the analogous dependence on reciprocal square root of grain size or crack size of fracture strength measurements reported for steel and other potentially brittle materials. The two dependencies have much in common. For onset of cleavage in steel, attention is focused on relationship of the essentially athermal fracture stress compared with a quite different viscoplastic yie...

A unified statistical dislocation-mediated crystal plasticity model is proposed to understand how the sample size affects yield strength of metals in different systems, namely, single crystals, columnar-grain structured thin films, and polycrystals. The takes into account randomness pre-existing dislocation network, grain orientation, predict as a function extrinsic (i.e. dimensions) intrinsic ...

Specific surface area is more informative than grain size for fine-grained sediments where Ss > 1 m2/g. In fact, specific plays a central role in engineering properties and processes soils, including pore bioactivity; fabric, plasticity, rheology; hydraulic electrical conductivity; compressibility residual friction angle; all forms of coupled processes. This research advanced dye adsorption met...

The mesoscopic constitutive behavior of face-centered cubic metals as a function of the system characteristic dimension recently has been investigated experimentally. Strong size effects have been identified in both polycrystalline submicron thin films and single crystal micro pillars. The size effect is manifested as an increase in strength and hardening rate as the system dimensions are decre...

A multiscale computational model is developed for determining the elasto-plastic behavior of polycrystal metals by employing a single crystal plasticity constitutive model that can capture the microstructural scale stress field on a finite element analysis (FEA) framework. The generalized method of cells (GMC) micromechanics model is used for homogenizing the local field quantities. At first, t...