The transition point between the Harrison type-A and type-B kinetics regimes as well as the emerging intermediate AB transition regime had been analyzed in detail by making use of lattice Monte Carlo simulations of tracer depth concentration profiles as a function of diffusion time and distance between grain boundaries. Harrison type-B to type-C kinetics regimes in the transient grain boundary diffusion problem were analyzed here using the parallel slabs model and lattice Monte Carlo numerical simulation. The transition point where the Harrison type-B kinetics regime last occurred (transition point between the Harrison type-B kinetics and the type-BC kinetics) was estimated at α (= 0.5δ(D1t)-1/2) = 0.1. The Harrison type-C grain boundary diffusion kinetics regime was also analyzed using lattice Monte Carlo simulated concentration depth profiles. The transition point where the Harrison Type-C kinetics regime first occurred (transition point between the type-BC kinetics and the Harrison type-C kinetics) was estimated at α = 5.0. Therefore an intermediate type-BC regime could be expected to occur between 0.1 < α < 5.0. Preliminary results for the cubic grain model showed that the interval for the intermediate type-BC regime was somewhat narrower for this model and occurred at 0.5 < α < 5.0.

Parametric Analysis of the Classification of Harrison Kinetics Regimes in Grain Boundary Diffusion. I.V.Belova, G.E.Murch, T.Fiedler: Defect and Diffusion Forum, 2010, 297-301, 1226-31