Surface segregation of Pb in the annealed Al-foils has been studied by Rutherford back scattering spectroscopy (RBS) and transmission electron microscopy (TEM). High-purity Al-foils containing 100 mass-ppm Pb were heat-treated for 1 h or 4 h at 540°C. Almost all of Pb segregate in a thin layer, 0.1 μm from the surface. Lead contents in the Pb-enriched surface layers were estimated to be 0.1∼0.14 at% Pb which were about 100–fold higher than the initial bulk concentration. TEM observations show that Pb-particles are formed at foil surfaces and their size increases from about 80 nm to 240 nm when final annealing time increases from 1 h to 4 h at 540°C. The Pb particles have a cube-cube orientation relationship with Al matrix and are bounded by {100} and {111} facets.
