Diffusion of 65Zn in Mg and in Mg–x Al solid solutions

Abstract

AbstractHeterodiffusion of 65Zn in Mg, Mg–x Al (x = 1.77, 3.9 and 9 wt% Al) and the commercial AZ91 alloy was studied in the temperature interval 498–848 K by serial sectioning and residual activity methods. The concentration and temperature dependence of the Zn bulk diffusion coefficient D is described by the relation D = exp (0.1c Al – 9.16) exp (–125.8 kJ mol–1/RT ) m2 s–1 (c Al – concentration of Al in wt%). The Zn grain boundary diffusivity P = sδD b (s – segregation factor, δ – grain boundary width and D b – diffusion coefficient in the grain boundary) was also determined and obeyed the Arrhenius law P = 7.2 × 10–15 exp (–46 kJ mol–1/RT ) m3 s–1. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)