CPC C23C 22/66 (2013.01) [C09D 5/12 (2013.01); C23C 22/12 (2013.01); C23C 22/361 (2013.01); C23C 22/56 (2013.01); C23C 22/73 (2013.01); C23C 22/78 (2013.01); C23C 22/82 (2013.01); C23C 22/07 (2013.01)] | 15 Claims |
1. A system for treating a multi-metal article comprising:
(a) a first conversion composition for treating at least a portion of a non-aluminum metal surface of the multi-metal article, the first conversion composition comprising phosphate ions and zinc ions and being substantially free of fluoride; and
(b) a second conversion composition for treating at least a portion of an aluminum metal surface of the multi-metal article, the second conversion composition comprising a lanthanide series metal cation and an oxidizing agent; and/or
(c) a third conversion composition for treating at least a portion of the aluminum surface, the third conversion composition comprising an organophosphate compound, an organophosphonate compound, or combinations thereof;
wherein the multi-metal article comprises (1) an article that comprises the non-aluminum metal surface and the aluminum metal surface, (2) a first article comprises the non-aluminum metal surface and a second article comprises the aluminum metal surface, or (3) both (1) and (2); and
wherein the first conversion composition does not deposit on the aluminum metal surface.
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