Abstract: This invention relates to a composition and a method for preparing an organic protective coating on a Cr(lll) conversion layer which is localized on aluminium or an aluminium alloy to enhance corrosion protection. The composition is an alkaline aqueous solution which contains at least one corrosion inhibitor, a buffering agent and at least one organic film former. According to the method of the present invention, the composition is used for post-treating of a Cr(lll) conversion layer on aluminium or an aluminium alloy and on anodized aluminium or an anodized aluminium alloy.

Abstract: The invention relates to a substrate with a corrosion resistant coating comprising at least one nickel layer and at least one chromium layer as finish. Between these layers, at least one tin-nickel alloy layer is deposited for suppression of corrosion reactions determined by CASS and Russian mud tests. The invention relates also to a method for producing such substrates with corrosion resistant coating.

Abstract: A zinc electroplating bath includes zinc ions and a brightening agent. The brightening agent is a polyamine or a mixture of polyamines that include a quaternary ammonium group.

Abstract: An apparatus (12) for applying a zinc or zinc-alloy electroplate to a workpiece comprises an electroplating bath (16) having a pH more than about 14. The electroplating bath includes zinc ions and an additive. A cathode workpiece (18) is in the bath. An anode assembly (20) contacts the bath. The anode assembly includes an anolyte and an insoluble metal anode in the anolyte. The additive is capable of electrolytically breaking down upon contact with the anode. The anode assembly inhibits the electrolytic breakdown of the additive.

Abstract: A zinc electroplating bath includes zinc ions and a brightening agent. The brightening agent is a polyamine or a mixture of polyamines that include a quaternary ammonium group.

Abstract: A disk for a hard disk drive is provided. The disk comprises a substrate comprising aluminum, and a coating layer disposed over the substrate. The coating layer comprises an alloy of Ni, X1 and X2, wherein X1 comprises one or more elements selected from the group consisting of Ag, Au, B, Cr, Cu, Ga, In, Mn, Mo, Nb, Pb, Sb, Se, Sn, Te, W, Zn and Zr, and wherein X2 comprises either B or P, and wherein X1 and X2 do not comprise the same elements.

Abstract: The invention relates to polymers which comprise at least partially cross-linked main chains constructed from repeat units of the general formula I and possibly repeat units of the general formula II and also possibly repeat units comprising five- or six-membered aza aromatics or nitrogen-containing heterocycles. Polymers of this type are used as additive in electroplating baths since these enable a better layer thickness distribution of the electroplated layer.

Abstract: The invention relates to polymers which comprise at least partially cross-linked main chains constructed from repeat units of the general formula I and possibly repeat units of the general formula II and also possibly repeat units comprising five- or six-membered aza aromatics or nitrogen-containing heterocycles. Polymers of this type are used as additive in electroplating baths since these enable a better layer thickness distribution of the electroplated layer.

Abstract: The invention concerns a method for chemical attack of the surface of a plastic material with a solution based on sulphuric acid and chromic anhydride, characterised in that (i) the sulphuric acid concentration ranges between 500 and 760 g/l and (ii) the chromic anhydride concentration ranges between 30 and 200 g/l and (iii) the resulting acidity is at least equal to 13 and at most equal to 16.

Abstract: The invention relates to a dip comprising an acid aqueous solution having no ammonium ion, fluoroborate ions or citrate ion and containing per liter: between 10 and 60 g of Zn2+ ions and between 20 and 100 g of Mn2+ ions. The invention is characterised in that it comprises a buffer agent that maintains the pH at a value of between 3 and 7, preferably between 4.5 and 6 or better still between 4.8 and 5.5, and another agent, different from the buffer agent, which is used to bring together the deposition potentials of couple Zn/Zn2+ and couple Mn/Mn2+. The inventive dip used to deposit a Zn and Mn alloy by electrolysis.