| 摘要 |
<p>Corrosion resistant conversion coatings can be deposited on a metal, especially, zinc, tin, cadmium, iron, steel, magnesium, copper, nickel, silver or aluminium or their alloys, substrate by contacting the substrate with an aqueous solution containing Fe<II>, Fe<III>, Ni<II> or especially Cr<III> ions and an oxidizing agent. The solution is either dilute, less than 0.1 M, in respect of the ions and/or contains a weak complexing agent for the ions. Especially good corrosion resistance notably on Zn e.g. galvanized steel, substrates is obtained by including boric acid in the solution. The coatings are preferably baked to age them and may subsequently be lacquered, painted or laminated to plastics materials.</p> |
