The migration of Zn was studied at 180 to 235C by measuring concentration profiles across grain boundaries which were essentially perpendicular to the surface of thick Al foils. The latter were coated with Zn and were annealed for a time which was sufficient to produce a steady flow of Zn, along the boundaries,

from one side of the foils to the other. The Zn concentration was determined by carrying out energy dispersive X-ray analyses. The results could be described by:

D (cm2/s) = 1.8 x 10-2 exp[-26.7(kcal/mol)/RT]

and agreed well with values which were obtained by extrapolating high-temperature data.

S.Varadarajan, R.A.Fournelle: Acta Metallurgica et Materialia, 1992, 40[8], 1847-54