Grain boundary radiotracer diffusion of Ge-71 and Ga-72 in Al and Al-Ga alloys

作者：Lohmann M; Divinski SV^*; Herzig C

来源：Zeitschrift fur Metallkunde, 2005, 96(4): 352-357.

• grain boundary diffusion
• Ge
• Ga
• Al
• AI(Ga) alloys
• grain boundary wetting

Grain boundary (GB) solute diffusion of Ge and Ga in Al polycrystals was investigated by the radiotracer serial sectioning technique using Ge-71 and Ga-72 isotopes. The diffusion measurements were carried out under conditions of Harrison's B-kinetics regime in the temperature range 450-680 K. The measured triple products P = sδ D-gb (S is the segregation factor, 6 the GB width and D-gb the GB diffusivity) were found to follow the Arrhenius law with pre-exponential factors and activation enthalpies of 6.36 x 10(-14) (5.33 x 10(-13)) m(3)/s and 53.6 (54.8) kJ/mol for Ge (Ga), respectively. Alloying of Al by Ga results in a slight increase of the Ge GB diffusivity by a factor of two to three at 576 K within the total Ga content up to 1 at.%. This result does not confirm the appearance of a liquid-like GB layer in the Al - Ga alloys studied.

• 出版日期2005-4