摘要 |
A bath for pre-treatment of light metals that form oxide layers, before electroless (chemical) metal deposition is an aqueous bath containing phosphorous acid. The bath is used in the following process for electroless deposition of nickel: (1) Degreasing by boiling (2) Rinsing (3) Pickling (4) Rinsing (5) Treatment in aqueous bath containing phosphoric acid (6) Rinsing with water (7) Chemically nickel plating (8) Rinsing. The light metal articles are packed in a drum that is immersed and rotated in the pre-treatment bath. Current and voltage are applied to a light metal bar that is attached to a non-rotating place on the drum. |