A study of conversion coating development on aluminium in chromate/fluoride solutions using secondary ion mass spectrometry*

摘要: Abstract A Cameca Ion Analyzer has been used to examine aluminium surfaces, covered by 73 nm thick barrier type anodic films, after natural immersion for 1–15 min in a chromate/fluoride conversion coating solution at 293 K. The produced is essentially amorphous chromium-containing material, probably largely hydrated chromic oxide, but contains cellular-type structure with and fluoride, as complex oxyfluoride, concentrated the inter-cellular regions. major role of F − ion remove initial oxide film, maintain surface active permit nucleation lateral growth over it. more aggressive towards other alumina than CrO 4 2− PO 3− ions, without appearing enter film material per se , also substrate C1 ion, acting initially flaws undermining film.