Electroplating formulation and process for plating iron onto aluminum/aluminum alloys

An electroplating bath solution for use in electroplating an iron layer onto an aluminum or aluminum alloy surface of a cathode, the bath solution comprising:

• Fe+2 having a concentration ranging from about 0.65 to about 2.5 moles per liter of solution;
• at least one anion associated with the Fe+2 ion;
• a reducing agent in an amount sufficient to prevent oxidation of Fe+2 to Fe+3;
• Cl− in an amount sufficient to promote dissolution of an anode and increase the conductivity of the solution;
• a wetting agent in an amount sufficient to prevent pitting of the cathode surface;
• and
• boric acid in a concentration of from about 50 to about 90 grams per liter of solution.

A method for electroplating an iron layer onto an aluminum or aluminum alloy surface of an aluminum or aluminum alloy substrate cathode, said method comprising:

• providing an activation/electroplating bath solution comprising:
• (1) Fe+2 having a concentration ranging from about 0.65 to about 2.5 moles per liter of solution;
• (2) at least one anion associated with the Fe+2 ion;
• (3) a reducing agent in an amount sufficient to prevent oxidation of Fe+2 to Fe+3 ;
• (4) Cl− in an amount sufficient to promote dissolution of an anode and increase the conductivity of the solution;
• and
• (5) a wetting agent in an amount sufficient to prevent pitting of an aluminum electroplated surface;
• activating said surface of said cathode by immersing said cathode in said solution;
• immersing the anode in said solution;
• electroplating said iron layer directly onto said activated aluminum or aluminum alloy surface of said cathode in said solution;
• and
• removing impurities from said solution.

A method of improving throughput of an electroplating bath solution for use in electroplating an iron layer onto an aluminum or aluminum alloy surface of a cathode, the method comprising:

• providing an electroplating bath solution comprising:
• Fe+2 having a concentration ranging from about 0.65 to about 2.5 moles per liter of solution;
• at least one anion associated with the Fe+2 ion;
• a reducing agent in an amount sufficient to prevent oxidation of Fe+2 to Fe+3;
• Cl− in an amount sufficient to promote dissolution of the anode and increase the conductivity of the solution;
• and
• a wetting agent in an amount sufficient to prevent pitting of an aluminum electroplated surface;
• and
• adding boric acid in a concentration of at least about 50 grams per liter of solution, the concentration of boric acid increasing throughput of the electroplating bath.