| 摘要 |
A bath for pre-reatment of light metals (eg Al, Mg, Ti) that form oxide layers, before electroless (chemical) metal deposition, of eg Ni, Cu, Au, 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. As illustrated a metal bar 22, attached to the downward bending end portion 28 of a hollow isolation tube 23, is positioned to contact the bulk materials 30 in the rotatable drum 15. <IMAGE> |
