1,240,183. Electro-plating with aluminium. NIPPON KOHAN K.K. Oct. 14, 1968 [Oct .25, 1967] No.48482/68. Heading C7B. A dense Al plating is electro-plated on to a metal (e.g. steel) substrate as cathode using an Al anode and a bath comprising a molten Al salt. The method includes the step of electrolytically oxidizing Al ions of low valency formed in the bath to trivalent Al ions by one of the following means: - (a) passing D. C. between a Pt plate anode and an independent Al cathode in the bath, (b) employing an Al rod as the anode or (c) passing A. C. between a Pt electrode and the substrate, e.g. a Pt wire coiled about the substrate. HCl gas may be blown into the bath during the plating operation. The electro-plating may be at a current density of 2A/ dmSP2/SP. In the Examples the baths are of (1) AlCl 3 , NaCl and KCl at 160‹C., (2) AlCl 3 and NaCl at 150‹C. and (3) AlCl 3 and NaCl at 160‹C.
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