Diffusion of 65Zn in Mg and in Mg-xAl solid solutions

Heterodiffusion of Zn-65 in Mg, Mg-xAl (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) m(2) s(-1) (C-Al - concentration of Al in wt%). The Zn grain boundary diffusivity P = s delta D-b (s - segregation factor, delta - grain boundary width and D-b - diffusion coefficient in the grain boundary) was also determined and obeyed the Arrhenius law P = 7.2 x 10(-15) exp (-46 kJ mol(-1)/RT) m(3) s(-1). (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.