Abstract
Diffusion characteristics of Ge in Mg and Mg-1.8wt.%Al alloy were studied. The measurement was carried out by serial sectioning and by residual activity methods in temperature interval 448–848 K. Due to extremely low bulk solubility, Ge diffusion occurs almost exclusively in grain boundaries (GB’s). Hence, Ge diffusion coefficient D_b in GB’s was directly evaluated at higher temperatures, whereas triple product P = D_bsδ (s, δ – segregation factor and GB thickness, respectively) was measured in low-temperature region. Obtained values of D_b and P enabled to make a rough estimation of segregation factor s of Ge to GB’s.

Key words
magnesium alloys, diffusion, grain boundaries, interface segregation

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