Influence of Al and Mg on High-temperature Oxidation Resistance of Zinc Alloy Electroplating Solution

The influences of Al and Mg on surface oxidation of zinc alloy electroplating solutions are studied by SEM and XRD methods, using 8 kinds of zinc alloy electroplating solutions with different Al and Mg contents.The results indicate that increasing of Mg will aggravate oxidation of the electroplating solutions, while increasing of Al will do the opposite.In an alloy electroplating solution with 0.5%Mg, when Al is ≥ 0.1%, mixed oxides MgAl₂O₄phase appears in the oxide film, which will reduce MgO in the film.Adding 0.075%Al to an electroplating solution with 0.5%Mg will bring a plating film with good high temperature oxidation resistance.