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Elastic recoil detection analysis (ERDA), RBS and TEM study of barrier film formation on Al–4.5 at.% Mg–0.05 at.% Cu alloy
Author(s) -
Thompson G. E.,
Skeldon P.,
Wood G. C.,
Zhou X.,
Kreissig U.,
Wieser E.,
Habazaki H.,
Shimizu K.
Publication year - 1999
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199901)27:1<57::aid-sia464>3.0.co;2-j
Subject(s) - elastic recoil detection , magnesium , alloy , copper , transmission electron microscopy , materials science , anodizing , analytical chemistry (journal) , electrolyte , ion , magnesium alloy , anode , thin film , metallurgy , aluminium , chemistry , nanotechnology , electrode , organic chemistry , chromatography
The influences of magnesium upon the formation ofbarrier‐type anodic films on an Al–4.5 at.%Mg–0.05 at.% Cu alloy have been examined by elasticrecoil detection analysis, Rutherford backscattering spectroscopy andanalytical transmission electron microscopy. The results reveal thatmagnesium species are distributed uniformly throughout the anodicalumina film, with magnesium species migrating outwards in the filmapproximately twice as fast as Al 3+ ions. Uponreaching the film surface, the magnesium species are ejected into theelectrolyte under the particular conditions of anodizing, whereas Al 3+ ions are retained within the film. The oxidation ofmagnesium results in voids at the alloy/film interface, which areprobably associated with the low Pilling–Bedworth ratio ofMg/MgO relative to that of Al/Al 2 O 3 .The voids are formed in the presence of a high enrichment of copper(to 1.0×10 19 Cu atoms m ‐2 ) in the alloy region immediately beneath the anodic film,with copper species (which migrate outward faster than Al 3+ ions) present throughout the anodic film.© 1999 John Wiley & Sons, Ltd.