Method for electro-chemical coating of a surface of a workpiece in section-wise manner through deposition of a layer, comprises continuously or discontinuously changing the current density in time-dependent manner

The method for electro-chemical coating of a surface of a workpiece in section-wise manner through deposition of a layer, which has a metal from an ionic fluid containing metal ions, comprises continuously or discontinuously changing the current density in time-dependent manner so that metal crystallites of different size are deposited in temporal sequence. The current density during the deposition is 120 seconds. The base current density is varied that is optionally superimposed to a pulse component. The base current density is varied between a minimal value and a maximal value. The method for electro-chemical coating of a surface of a workpiece in section-wise manner through deposition of a layer, which has a metal from an ionic fluid containing metal ions, comprises continuously or discontinuously changing the current density in time-dependent manner so that metal crystallites of different size are deposited in temporal sequence. The current density during the deposition is 120 seconds. The base current density is varied that is optionally superimposed to a pulse component. The base current density is varied between a minimal value and a maximal value that distinguish to a factor of 3. The base current density is varied within a variation time between the minimal value and the maximal value of 120 seconds. The pulse component is superimposed that comprises a sequence of positive and or negative impulses, impulses with an amplitude of 70% of the minimal value of the base current density and impulses with a duration of 10 milliseconds. The current density has a pulse portion and optionally has a base current density, where the current density, the duration and/or the pulse interval of the impulses are varied. The metal crystallites are deposited that consist of aluminum, magnesium, titanium, zinc-magnesium alloys, aluminum-magnesium alloys, aluminum-zinc alloys and/or zinc-titanium alloys. An independent claim is included for a workpiece having a metal coating.