| 摘要 |
<p>KGW (CASE 1242) DC PLATING ON ALUMINUM ALLOYS - In accordance with certain of its aspects, the process of this invention for plating aluminum comprises contacting said aluminum with an aqueous activating bath containing a stannate salt selected from the group consisting of sodium stannate and potassium stannate in a concentration of about 40 grams per liter of tin as stannate; of at least one member of the group consisting of sodium and potassium hydroxide in a concentration of from 1.2 grams per liter to 12 grams per liter; and 0.01 gram per liter to 25 grams per liter of at least one member of the group consisting of methyl cellulose ethers, polyvinyl alcohols, polyethylene oxide, and polyethylene glycols; maintaining said aluminum and said aqueous bath in contact, thereby activating the surface of said aluminum, withdrawing from said aqueous bath said aluminum bearing a film of said aqueous bath, immersing said aluminum bearing said film as cathode in an alkaline bronze strike bath containing an anode thereby depositing a bronze strike plate on said aluminum, and establishing a negative potential on said aluminum bearing said film with respect to said anode prior to the time said aluminum is immersed in said alkaline bronze strike bath. - i</p> |
