Self-diffusion in naturally grown symmetrical  = 5 <001> tilt boundaries was studied by using 110mAg radio-tracers. A technique based upon the Bridgman method permitted the production of boundaries with a large area (8mm x 60mm). This allowed the measurement of the diffusion behavior parallel to, and perpendicular to, the tilt axis in specimens which were cut from the same bi-crystal. The diffusivity was measured, parallel and perpendicular to the tilt axis, at 593 to 876K. The data for the  = 53.1 {012} grain boundary obeyed:

D(m3/s) = 1.23 x 10-17exp[-37.4(kJ/mol)/RT]

and those for the  = 36.9 {013} boundary obeyed:

D(m3/s) = 6.44 x 10-13exp[-109.1(kJ/mol)/RT]

A slight anisotropy was found for the 36.9 boundary, but no anisotropy was observed for the 53.1 boundary.

J.Sommer, C.Herzig, T.Muschik, W.Gust: Acta Metallurgica et Materialia, 1995, 43[3], 1099-107