Patent ID: 11926899
Assignee: RAYTHEON COMPANY
Field: Surface technology, coating (Chemistry)
Classification: CPC C | IPC C

Claim 0:
1. A process for coating a surface of an aluminum containing material, comprising:
degreasing a surface of an aluminum containing material to produce a degreased surface;
treating the degreased surface in a high alkaline treatment immediately subsequent to the degreasing to produce an alkaline treated surface having smut on the surface, wherein the highly alkaline solution contains 15-60 g/l sodium hydroxide (NaOH), 5-20 g/l sodium bicarbonate (NaHCO3), 5-10 g/l sodium nitrate (NaNO3) with sodium sulfide (Na2S), triethanolamine (C6H15NO3) and potassium gluconate (C6H11KO7); and
treating the alkaline treated surface with a hydrothermal treatment immediately subsequent to the high alkaline treatment providing the surface of the aluminum containing material with a chromate-free coating.