The diffusion coefficient of Ag was measured during Ag precipitation from dilute solid solutions by using 110Ag radio-tracers at temperatures of between 327 and 363K (table 99). The activation energy (49.4kJ/mol) was smaller than the activation energy (60kJ/mol) for Ag diffusion in pure Pb but was in reasonable agreement with a published value (50kJ/mol) of the activation energy for the precipitation of Ag. The evidence for the suggestion that (Pb-Ag) pairs were the defects which were responsible for Ag migration during precipitation in these dilute alloys, and for Ag diffusion in pure Pb and Pb-Ag solid solutions, was considered.

A.Menaï, H.Amenzou, G.Moya, J.Bernardini: Acta Metallurgica et Materialia, 1994, 42[12], 4049-58

Table 99

Diffusivity of Ag in Pb-Ag