Metal article passivated by a bath having an organic activator and a film-forming element

A passivated article prepared by a method for the passivation treatment of a metallic surface, comprising:

• preparing an aqueous acidic substantially chloride-free bath having dissolved therein one or more film-forming agents at least one of which is a bath-soluble chromium-free film-forming agent selected from the group consisting of fluoride salts, oxalate salts, malonate salts, succinate salts, and combinations thereof, said chromium-free film-forming agent including a non-chromium film-forming element selected from the group consisting of aluminum, silicon, titanium, vanadium, iron, cobalt, molybdenum, cerium and combinations thereof, said bath also having dissolved therein a bath soluble organic activating agent selected from the group consisting of polyhydroxy carboxylic acids, polycarboxylic acids, salts of polyhydroxy carboxylic and polycarboxylic acids, transition element complex salts of polyhydroxy carboxylic and polycarboxylic acids, esters of polyhydroxy carboxylic and polycarboxylic acids, and combinations thereof, said organic activating agent, whether added as said film-forming agent, as said organic activating agent, or as any other bath additive, is present at a concentration up to about 0.3 weight percent, expressed as oxalic acid, per volume, based on the total bath volume, said bath including a strong acid and having an operative pH range between values high enough to avoid chemical polishing and etching of the metal surface and low enough to maintain a desired rate of passivation reaction;
• applying said aqueous acidic bath to a zinc surface to form a film by means of a passivation reaction between said non-chromium film-forming element and said zinc surface;
• and
• permitting said film to dry to a thin, adherent and coherent hydrophobic passivation coating.