A Monte Carlo method was introduced for the numerical analysis of tracer diffusion in the presence of isolated grain boundaries with a variable mesh in the direction perpendicular to the grain-boundary plane. A number of isoconcentration contour profiles was studied. Two different expressions for the angle between the isoconcentration contours and the grain boundary were derived for the instantaneous tracer source, using procedures analogous to the Fisher and Whipple approximations for the constant tracer source. Comparison with the numerical data was made. Both approximations overestimated the grain boundary diffusivity.

Diffusion in the Presence of Grain Boundaries: a Variable Length Scale Simulation Method. I.V.Belova, G.E.Murch: Materials Research Society Symposium – Proceedings, 2001, 677, AA7.20.1-6