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SSIMS, XPS and microstructural studies of ac‐phosphoric acid anodic films on aluminium
Author(s) -
Johnson D.,
Vickerman J. C.,
West R. H.,
Treverton J. A.,
Ball J.
Publication year - 1990
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/sia.740150605
Subject(s) - anodizing , x ray photoelectron spectroscopy , phosphoric acid , secondary ion mass spectrometry , aluminium , analytical chemistry (journal) , nucleation , protein filament , chemistry , static secondary ion mass spectrometry , materials science , ion , inorganic chemistry , metallurgy , chemical engineering , composite material , chromatography , organic chemistry , engineering
ac‐Phosphoric acid anodizing of aluminium results in the initial formation of a featureless barrier film on the metal surface, followed by nucleation and growth of a filament structure. The rate of filament growth and filament diameter are dependent upon the anodizing temperature. Static secondary ion mass spectrometry (SSIMS) and XPS indicate that organic contamination levels on all anodized surfaces are low regardless of anodizing temperature and that contaminant levels tend to decrease as anodizing proceeds. Apart from the very intense Al + in the positive ion spectra and the O − and OH − peaks in the negative ion spectra, SSIMS spectra were characterized by the appearance of a series of peaks from Al x O y H z fragments. Appearance of AlO + or AlOH + clusters in the positive ion spectra depended on the anodizing conditions. Both XPS and SSIMS confirm the presence of phosphates on the anodized surfaces but differences in results from the two types of analyses imply that unknown factors affect the concentration present. Low contaminant levels, corrosion inhibition from surface phosphates and the filamented topography developed will all affect the adhesive properties of the surface.