Abstract
Surface segregation of iron in high purity aluminum alloys, containing 50 and 280 ppm iron, was investigated by Rutherford back scattering spectroscopy (RBS) and transmission electron microscopy (TEM). The specimens were heat treated at various temperatures ranging from 423 K to 923 K for 72 ks in Ar atmosphere. The surface segregation of iron by heat treatment was detected by RBS measurement. The strongest segregation was observed in the Al–280 ppmFe annealed at 723 K for 72 ks. The surface segregation quantities in Al–50 ppmFe alloy was smaller than those in Al–280 ppmFe alloy, but the degree of segregation (segregation concentration/bulk concentration) in Al–50 ppmFe alloy was larger than that in Al–280 ppmFe alloy. TEM–EDX indicated that almost of iron segregated at the interface between oxide film and the matrix, but a few iron in the oxide films just above aluminum matrix was detected.
