Conclusion

After recalling a few basics about the mechanisms of intergranular diffusion, this article focuses on the difference in diffusional behavior of grain boundaries according to their structures. First of all, it presents the various responses of joints to diffusion, depending on their mechanical description in terms of intergranular dislocations; the interesting interpretations of the results are not, however, sufficient to account for many behaviors, since diffusion is a property attached to the core of the grain joint.

For this reason, it is necessary to relate diffusion to the configuration of atoms in the joint region, described in terms of structural units. A distinction can be made between grain boundaries with a low angle of disorientation, a few rare singular boundaries, and general boundaries. The latter exhibit higher diffusion coefficients than the former,...