Method of electroplating aluminum and its alloys

US4071415A · kind A · utility

Inventor

• Jack Wong · Chicago, US

Key dates

• Filing date: Oct 21, 1976
• Grant date: Jan 31, 1978
• Expiry date: Oct 21, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25D3/44
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

Aluminum or an alloy thereof is electroplated upon electrically conductive substrates by immersing the substrate as a cathode in a novel stable electrolyte, made as follows: PA1 A. reacting aluminum with a hydrogen halide such as HCl, HBr, or HI (but preferably hydrogen bromide) or reacting aluminum with a halogen such as Cl.sub.2, Br.sub.2, or I.sub.2 (but preferably bromine), in the absence of water, but in one of the following single organic, non-Lewis base solvents or mixtures thereof: benzene, toluene, carbon disulfide, cyclohexane, dimethyl sulfide, tetrahydrofuran, diiodoethane, toluene-cyclohexane (1:1), benzene-cyclohexane (1:1), tetrahydrofuran (THF): benzene (4:1) and toluene-CS.sub.2 (3:1) to form an intermediate aluminum halide cation in solution, the concentration of the aluminum cation and the concentration of hydrogen ion, in solution being respectively, below about 7.5 M and 0.5 M and preferably being, respectively, below about 4.2 M and 0.1 M; and PA1 B. then adding a restricted amount, preferably less than about 16 mole % relative to the initial quantity of aluminum added, of a metal halide, MX where M=Li, Na, or K and X=Cl, Br, or I; or where MX is a special hal…