Computer simulation methods were used to model a series of grain boundaries with the aim of establishing a procedure for the generation of grain boundaries and for the calculation of the effect of high pressures and temperatures upon the structure, energies and diffusivities which were associated with these boundaries. The simulations predicted that temperatures of up to 1200K had little effect upon the structure and energies, whereas pressures of up to 40GPa had a large effect. That is, such pressures caused the free energy of formation to increase with pressure, for all of the grain boundaries that were studied. In addition, the (310), (410) and (510) grain boundaries underwent structural changes which minimized the dilation of the grain boundary. In the case of the (410) and (510) grain boundaries, this structural change was found to be irreversible when the pressure was released.

D.J.Harris, G.W.Watson, S.C.Parker: Philosophical Magazine A, 1996, 74[2], 407-18