Abstract Hydrogen-grain-boundaries interactions and their role in intergranular fracture are well accepted as one of the key features understanding hydrogen embrittlement a large variety common engineer situations. These implicate some fundamental processes classified segregation, trapping diffusion solute which can be studied function grain boundary configuration. In present study, we carried ...

The three-dimensional interfacial network of grain boundaries in polycrystalline nickel has been characterized using a combination of electron backscatter diffraction mapping and focused ion beam serial sectioning. These data have been used to determine the relative areas of different grain boundary types, categorized on the basis of lattice misorientation and grain boundary plane orientation. ...

The damage accumulation behavior of different grain boundary structures in Inconel 690 (Ni-29wt%Cr-9wt%Fe) was investigated in the presence of large, localized plastic strains induced by nanoindentation. Spatially-resolved hardness was measured as a function of lateral distance from ‘random’ high-angle grain boundaries and twin boundaries. The confinement of induced defects between the indenter...

Three different aluminum–iron alloys were produced by electron-beam deposition with the iron content in the range 1.15–1.71 at.%. These alloys did not contain any identifiable iron-bearing particles, and exhibited full density with high-angle grain boundaries in the micrometer range, and a sub-grain size typically smaller than 100 nm. The tensile deformation characteristics of the alloys were e...

The major objective of the present study was to investigate creep fracture process a copper tricrystal having 〈110〉-tilt Σ3, 3, 9 grain boundaries. Creep tests at 0.81 TM (TM: melting temperature on absolute scale) under 4 MPa tensile stress were carried out for three samples prepared from same tricrystal. Grain-boundary sliding occurred along only Σ9 boundary, and triple junction boundaries co...

The grain boundary character distribution (GBCD) of a fully-orthorhombic (O) Ti–25Al–24Nb (at.%) microstructure was investigated using electron backscatter diffraction (EBSD). The fine-grained (GS=17 lm) equiaxed microstructure was processed by hot forging and hot-rolling operations performed below the body-centered cubic (bcc) phase transus temperature followed by heat treatment in the O-phase...

The grain contact force, the key player in determining the mechanical properties of grain materials, depends on the elastic modulus and deformation (δ) of grains. However, our knowledge on their relationship in a three-dimensional granular medium is limited mainly owing to the difficulty of realizing direct experimental investigation. Using a simple force vibration technique, we measure the dis...

S U M M A R Y The formation of narrow, rapidly deforming plate boundaries separating strong plate interiors are integral components of the generation of plate tectonics from mantle convection. The development of narrow plate boundaries requires the interaction of a non-linear rheology and convection. One such non-linear rheology is two-phase damage theory which employs a nonequilibrium relation...

Structural transformation in gallium arsenide nanocrystals under pressure is studied using molecular-dynamics simulations on parallel computers. It is found that the transformation from fourfold to sixfold coordination is nucleated on the nanocrystal surface and proceeds inwards with increasing pressure. Inequivalent nucleation of the high-pressure phase at different sites leads to inhomogeneou...

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