Acid dip for zinc-manganese alloy electrodeposition

摘要

The invention relates to a dip comprising an acid aqueous solution having no ammonium ion, fluoroborate ions or citrate ion and containing per liter: between 10 and 60 g of Zn²⁺ ions and between 20 and 100 g of Mn²⁺ ions. The invention is characterised in that it comprises a buffer agent that maintains the pH at a value of between 3 and 7, preferably between 4.5 and 6 or better still between 4.8 and 5.5, and another agent, different from the buffer agent, which is used to bring together the deposition potentials of couple Zn/Zn²⁺ and couple Mn/Mn²⁺. The inventive dip used to deposit a Zn and Mn alloy by electrolysis.