Electroplating solutions for the electrodeposition of aluminum and method of making same
US4152220A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 9, 1978 |
| Grant date | May 1, 1979 |
| Priority date | — |
| Expiry date | Jan 9, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D21/18
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
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 by (a) reacting aluminum with a hydrogen halide or a halogen and hydrogen halide, in the absence of water, but in one of several organic, non-Lewis base solvents or mixtures thereof 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 5.0 M and 0.4 M and preferably containing an aluminum cation concentration extending between 2.7 M and 4.2 M and a [H.sup.+ ] ion concentration extending between about 0.01 M and about 0.3 M, the exact maximum amount of [H.sup.+ ] ion concentration depending upon the aluminum ion concentration (there is a direct, substantially linear, relationship between the [Al.sup.+3 ] ion concentration and [H.sup.+ ] ion concentration); and (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 halide such as beryllium br…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.