Concentration Dependence of Grain Boundary Diffusion

According to different experimental data the grain boundary diffusion the triple product (P) can change in opposite directions after alloying. In this paper the analysis of the effect of alloying for different systems is proposed. It was shown that in Al-based system (Cu diffusion in Al, Zn diffusion in Al) the P value increases with alloying while the solidus temperature according to the phase diagram decreases, in other systems no such tendency can be seen. Estimations based on the segregation factor value demonstrate that some structural effect must be proposed in addition to describe the experimental results.