Orientation imaging microscopy has been used to investigate the effects of Nb doping on the grain boundary plane distributions in TiO2 (rutile). By comparing the grain boundary plane distribution of the undoped material with theoretical estimates of grain boundary energy anisotropy of pure rutile, it is possible to show that the frequency of grain boundary planes is inversely correlated with gr...

There is a growing body of the literature that suggests that there are grain boundary structures that exist in ceramic systems that are not predicted by bulk thermodynamics. Transitions between the various grain boundary structures are not well understood either experimentally or theoretically. This study identifies six different types of grain boundary structures present in the alumina system....

Wepresent first-principles simulations of single grain boundary reflectivity of electrons in noble metals, Cu and Ag. We examine twin and non-twin grain boundaries using nonequilibrium Green’s function and first principles methods. We also investigate the determinants of reflectivity in grain boundaries by modeling atomic vacancies, disorder, and orientation and find that both the change in gra...

The atomic and the electronic structures of the (5 ~210! @001# tilt grain boundary in Ni3Al, with and without a hydrogen impurity, have been calculated using the full potential linearized-augmented plane-wave method. The strain field normal to the boundary plane and the excess grain boundary volume are calculated and compared with the results obtained using the embedded-atom method ~EAM!. The i...

We use numerical experiments to analyze the kinetics of grain boundary wetting in polycrystalline aggregates under the influence of an external applied shear stress. Grain boundary wetting is driven by the stress concentration at the tip of the fluid front. The extent of wetting of favorably oriented grain boundaries depends on the fluid mobility number b, which is defined as the ratio of the r...

Experiments were performed to observe the effects of processing and composition on the grain boundary character distribution (GBCD) of SrTiO3, MgO, and Ni. Anisotropic interfacial energies and, in the case of nickel, crystallographic constraints, are expected to influence the evolution of the GBCD during processing. Interrupted grain growth experiments were performed with SrTiO3 to observe the ...

Non-uniform grain boundary sliding can induce strain and rotation incompatibilities at perfectly planar interfaces. Explicit analytic expressions of stress and lattice rotation jumps are thus derived at a planar interface in the general framework of heterogeneous anisotropic thermo-elasticity with plasticity and grain boundary sliding. Both elastic fields are directly dependent on in-plane grad...

Grain boundary motion may be accompanied with vacancy generation [1–4]. A typical case where a moving grain boundary produces vacancies is in primary recrystallisation, when the growth of a recrystallised grain at the cost of a grain with a large dislocation density involves release of excess free volume. Vacancies are also generated during grain growth, when the total volume of the grain bound...

The sensitization and subsequent intergranular corrosion of Al-5.3 wt.% Mg alloy has been shown to be an important factor in stress corrosion cracking of Al-Mg alloys. Understanding sensitization requires the review of grain boundary character on the precipitation process which can assist in developing and designing alloys with improved corrosion resistance. This study shows that the degree of ...

A mesoscale, variational simulation of grain growth in two-dimensions has been used to explore the effects of grain boundary properties on the grain boundary character distribution. Anisotropy in the grain boundary energy has a stronger influence on the grain boundary character distribution than anisotropy in the grain boundary mobility. As grain growth proceeds from an initially random distrib...