Abstract: The present invention is directed toward an electrolyte which allows for electrolytically producing a black metal layer consisting of rhodium and ruthenium. The present invention also relates to a method for producing a corresponding article, and to the use of the electrolyte.

Abstract: The present invention is directed toward an electrolyte which allows for electrolytically producing a black metal layer consisting of rhodium and ruthenium. The present invention also relates to a method for producing a corresponding article, and to the use of the electrolyte.

Abstract: The invention relates to a ruthenium electrolyte which is suitable for the deposition of decorative and industrial layers having a particular blackness. The invention further relates to the use of the electrolyte of the invention in a process for the deposition of decorative and industrial layers of ruthenium having a particular blackness (“black ruthenium) on jewelry, decorative goods, consumer goods and industrial articles. The invention therefore likewise relates to corresponding layers and the articles coated in this way. The electrolyte is characterized in that it operates in the weakly acidic to alkaline pH range.

Abstract: The production of oxidation-stable and mechanically strong metal layers having a black color presents a particular challenge in the area of electrochemical finishing, especially since there are only a few metals which are suitable for this purpose. A possibility which is not hazardous to health, in contrast to nickel, and is economical compared with rhodium is the electrochemical production of black ruthenium layers. The invention provides an electrolyte and a method using this electrolyte for producing black ruthenium layers on pieces of jewelry, decorative goods, consumer goods and technical articles. The electrolyte is distinguished in that one or more phosphonic acid derivatives are used as a blackening additive. These maintain brightness. The degree of blackness of the resulting black ruthenium layer can be adjusted by the choice of the type and amount of the phosphonic acid derivatives used, while maintaining the desired brightness.

Abstract: The present invention is directed at a decorative article which has a particular noble metal-containing outer layer sequence. The invention further relates to a coating process suitable for this purpose. The layer sequence is characterized in that a palladium-containing bottom layer is followed by an electrolytically deposited alloy of ruthenium and an element of the group consisting of platinum and rhodium.

Abstract: The production of oxidation-stable and mechanically strong metal layers having a black color presents a particular challenge in the area of electrochemical finishing, especially since there are only a few metals which are suitable for this purpose. A possibility which is not hazardous to health, in contrast to nickel, and is economical compared with rhodium is the electrochemical production of black ruthenium layers. The invention provides an electrolyte and a method using this electrolyte for producing black ruthenium layers on pieces of jewelry, decorative goods, consumer goods and technical articles. The electrolyte is distinguished in that one or more phosphonic acid derivatives are used as a blackening additive. These maintain brightness. The degree of blackness of the resulting black ruthenium layer can be adjusted by the choice of the type and amount of the phosphonic acid derivatives used, while maintaining the desired brightness.