Diffusion Measurements of 67Ga in Polycrystalline Magnesium
Gallium grain boundary (GB) diffusion of Ga in polycrystalline magnesium was investigated by radiotracer residual activity technique using 67Ga isotope. The diffusion measurements were carried out under conditions of Harrison’s B-type kinetics in temperature range 639 – 872 K. An approximate evaluation procedure was proposed to calculate both volume diffusion coefficient Dv and GB diffusivity P = s dDb (s is the segregation factor, d the GB width and Db the GB diffusion coefficient). The obtained results showed the following linear Arrhenius relationships: Dv = 1.2 × 10-4 × exp (–134.3 kJ mol-1/RT) m2 s-1 and P = 3.8 × 10-9 × exp (–94.9 kJ mol-1/RT) m3 s-1, where R is universal gas constant and T the temperature. Obtained results were compared with literature data on Mg self-diffusion and with In impurity diffusion in magnesium.
M. Danielewski, R. Filipek, R. Kozubski, W. Kucza, P. Zieba, Z. Zurek
I. Stloukal and J. Čermák, "Diffusion Measurements of 67Ga in Polycrystalline Magnesium", Defect and Diffusion Forum, Vols. 237-240, pp. 1287-1292, 2005