An electrolyte for electropolishing metal surfaces, in particular workpieces, in particular made of titanium or titanium alloys such as nitinol. The electrolyte composition includes methanesulfonic acid and more than one polyhydric alcohol. The content of methanesulfonic acid is less than 15 vol %, the polyhydric alcohols having at least one diol and at least one polyalcohol. The at least one diol accounts for 20 to 65 vol %, and the at least one polyalcohol accounts for 20 to 65 vol %

A metal wire, which is one of a tungsten wire and a tungsten alloy wire, includes alkali metal on the surface thereof. The amount of alkali metal is at most 2.0 g per 1 g of the metal wire.

A tungsten wire that contains tungsten or a tungsten alloy is provided. An average width of surface crystal grains in a direction perpendicular to an axis of the tungsten wire is at most 98 nm. The tungsten wire has a tensile strength of at least 3900 MPa. The tungsten wire has a diameter of at least 100 m and at most 225 m.

Methods and devices for treatment of metal surfaces by means of electrically active solid particles that include a step of contact of the solid particles with the electrode of an electric source, a step of shooting the particles towards the metal surface to be treated and a step of transmission of electric charge of the particles on the metal surface to be treated. The transmission of the electricity between the electric source and the metal surface during the step of shooting preferably is by net charge of the particles or by electric conductivity by contact or by electric conductivity by means of voltaic arches. The current applied to the electrode is preferably a DC or a current that contains positive sections and negative sections.

A tungsten wire according to an embodiment is a tungsten wire made of a W alloy containing rhenium, and includes a mixture on at least a part of a surface thereof, the mixture contains W, C, and O as constituent elements, and taking a radial cross-sectional thickness of the mixture as A mm and a diameter of the tungsten wire as B mm, an average value of a ratio A/B of A to B is 0.3% to 0.8%.

A tungsten wire according to an embodiment is a tungsten wire made of a W alloy containing rhenium, and includes a mixture on at least a part of a surface thereof, the mixture contains W, C, and O as constituent elements, and taking a radial cross-sectional thickness of the mixture as A mm and a diameter of the tungsten wire as B mm, an average value of a ratio A/B of A to B is 0.3% to 0.8%.