Abstract: The invention relates to an electrolyte for electropolishing metal surfaces, said electrolyte comprising methanesulphonic acid and additionally at least one phosphonic acid, as well as to an electropolishing method for same.

Abstract: A substantially anhydrous electropolishing electrolyte solution that includes at least one sulfate salt. The substantially anhydrous electropolishing electrolyte solutions described herein do not use water as a solvent; instead, such electropolishing electrolyte solutions use anhydrous alcohols and/or glycols as a solvent. For example, an electropolishing electrolyte solution, as described herein, may include an alcohol, at least one mineral acid, and at least one sulfate salt. The at least one sulfate salt can act as a source of sulfate ions to replenish sulfate ions consumed in the electropolishing process. Anhydrous sulfate salts can also act as water scavengers by reacting with water to form sulfate salt hydrates. Methods of electropolishing metal articles using such electropolishing electrolyte solutions are disclosed herein as well.

Abstract: The present invention relates to electrolytes for electrochemically polishing workpieces consisting of titanium, titanium alloys, niobium, niobium alloys, tantalum and tantalum alloys, which electrolytes contain sulfuric acid, ammonium bifluoride and at least one hydroxycarboxylic acid, and a method for electrochemical polishing.

Abstract: The present electropolishing electrolyte comprises an acid solution and an alcohol additive having at least one hydroxy group, wherein the contact angle of the alcohol additive is smaller than the contact angle of the acid solution on a metal layer under electropolishing. The alcohol additive is selected methanol, ethanol and glycerol, and the acid solution comprises phosphoric acid. The volumetric ratio of glycerol to phosphoric acid is between 1:50 and 1:200, and is preferably 1:100. The volumetric ratio is between 1:100 and 1:150 for methanol to phosphoric acid, and between 1:100 and 1:150 for ethanol to phosphoric acid. In addition, the acid solution further comprises an organic acid selected from the group consisting of acetic acid and citric acid. The concentration is between 10000 and 12000 ppm for the acetic acid, and between 500 and 1000 ppm for citric acid.

Abstract: An electrolytic solution formulation for an electropolishing process comprises at least an acid solution and an organic additive. The acid solution includes phosphoric acid or a mixture of phosphoric acid and sulfuric acid solutions, which can form a passivation layer on the surface of the metal layer. The additive comprises at least an acid group, wherein the diffusion of the organic additive is controlled in which a concentration gradient is formed in the opening of the metal layer. The electropolishing rate at the top of the opening is thereby faster than that at the bottom of the opening. The organic additive is selected from a monocarboxylic acid compound, a dicarboxylic acid compound, a tricarboxylic acid compound, a heterocyclic carboxylic acid compound or a sulfonic acid compound.

Abstract: A bath composition for the electropolishing of a metal surface made of nonalloyed titanium is disclosed. The bath composition may comprise sulfuric acid of 2 to 40% by volume, hydrofluoric acid of 10 to 18% by volume and acetic acid of 42 to 62% by volume.