-The effect of grain boundary regions on the total amount diffused during an exchange experiment has been numerically modeled. The total amount diffused increases when the grain size is decreased, and when the ratio of the grain boundary and lattice diffusion coefficients increases. Grain boundary migration increases the total amount diffused during part of the processing time. The numerical ca...

Garnet-like oxides having the formula Li7+X−YLa3−XAXZr2−YNbYO12 (A = Sr or Ca) were synthesized using a solid-state reaction, and their bulk and grain boundary resistivities were assessed by AC impedance measurements. A difference in grain boundary resistivity was identified between Sr and Ca materials, and so the grain boundaries were examined using electron probe microanalysis (EPMA). The dif...

In a previous experimental study on free-standing silicon thin film, it was observed that cleavage front transmission across a through-thickness grain boundary could be considerably constrained by film surfaces. As a result, the boundary toughness was much lower than its bulk counterpart. In this study, inspired by the observation of crack front behaviors at triple grain boundary junctions, we ...

In the process of alloy melting and vacuum pouring, impurity S element will inevitably be introduced into nickel-base superalloys, which cause adverse effects on microstructure properties cast superalloys. this paper, research progress in superalloys is summarized. The are described detail from experimental researches first-principles. reasons for grain boundary embrittlement caused by atom dis...

The grain boundary character distributions of selected doped aluminas were measured from normal and abnormal populations. The relative energies of the A-, C-, and Rplanes of undoped alumina were also measured. There is an inverse relationship between the population of grain boundaries and the relative energies of grain boundary planes in undoped alumina. This relationship is found to be qualita...

Nanocrystalline materials show a higher strain-rate sensitivity in contrast to the conventional coarse-grained materials and a different grain size dependency. To explain these phenomenon, a finite element model is constructed that considers both grain interior and grain boundary deformation of nanocrystalline materials. The model consist of several crystalline cores with different orientations...

We present a molecular dynamics simulation study of vacancy generation and emission from grain boundaries during curvature-driven grain boundary migration. The U-shaped half-loop bicrystal geometry is employed in order to maintain a constant driving force during boundary migration. Nonlinearities in plots of half-loop grain area versus time indicate the onset of non-steady-state behavior and va...

2014 Grain-boundary induced hardening mechanisms are illustrated by recent observations in silicon bicrystals. Basic features of grain boundary structure and grain boundary dislocations are given in the case of the 03A3 = 9 twin boundary. The dissociation of dislocations in grain boundaries and the possibility of direct dislocation transmission from one crystal to the other across the interface...

Three-dimensional electron backscatter diffraction data, obtained by serial sectioning a nickel– base superalloy, has been analysed to measure the geometric arrangement of grain boundary planes at triple junctions. This information has been used to calculate the grain boundary character distribution (GBCD) and the grain boundary energy distribution (GBED). The twin content from the three-dimens...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. A Monte Carlo simulation method is used to study the energetics and configuration of binary alloys when grain bound...