Plating bath for electrodeposition of aluminum and plating process making use of the bath
AssigneesNisshin Steel Co., Ltd., Mitsubishi Petrochemical Co., Ltd.
InventorSetsuko Takahashi
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Abstract
In the plating for electrodeposition of aluminum using a mixed molten salt bath comprising an aluminum halide and a quaternary ammonium salt, the mixed molten salt bath comprises from 20 to 80 mol % of the aluminum halide and from 20 to 80 mol % of a 1-alkyl- or 1,3-dialkylimidazolium halide, provided that the alkyl group has 1 to 12 carbon atoms, by the use of which the plating can be carried out at a high current density of not less than 30 A/dm.sup.2 without generation of burnt deposits, which has been difficult to carry out using the conventional molten salt bath. Addition of a halide of an alkali metal or alkaline earth metal, or an organic solvent, to the above plating bath can improve conductivity and also enhance uniform electrodeposition performance.
Claims12
A plating bath for electrodeposition of aluminum, comprising a molten mixture comprising from 20 to 80 mol% of an aluminum halide, and from 20 to 80 mol% of a 1-alkylimidazolium halide wherein the alkyl group has 1 to 12 carbon atoms, or a 1,3-dialkylimidazolium halide selected from the group consisting of 1-ethyl-3-methylimidazolium, 1,3-diethylimidazolium, 1-butyl-3-propylimidazolium and 1-decyl-3-ethylimidazolium halide.
A plating process for electrodeposition of aluminum, comprising carrying out plating bath for electrodeposition of aluminum, comprising a molten mixture comprising from 20 to 80 mol% of an aluminum halide, and from 20 to 80 mol% of a 1-alkylimidazolium halide wherein the alkyl group has 1 to 12 carbon atoms, or a 1,3-dialkylimidazolium halide selected from the group consisting of 1-ethyl-3-methylimidazolium, 1,3-diethylimidazolium, 1-butyl-3-propylimidazolium and 1-decyl-3-ethylimidazolium halide, in a dry oxygen-free atmosphere, using a direct current or pulse current, and under electrolysis conditions of a bath temperature of from 0.degree. to 300.degree. C. and a current density of from 0.01 to 50 A/dm.sup.2.
Dependencies are inferred from the claim text.