Electrolytic medium for electropolising and method of electropolising with said medium

A method for electropolishing a surface of a workpiece made of a conductive inorganic composite material, the method comprising:

• contacting the surface of the workpiece against a medium that comprises solid particles that each retains a liquid that has an electrical conductivity below 10 μS/cm, the solid particles being covered by an electrically non-conductive immiscible liquid;
• electrically connecting the workpiece to a first pole of an electrical power supply and electrically connecting the medium to a second pole of the power supply, the first and second poles having opposite polarity;
• and
• producing relative movement between the surface of the workpiece and the solid particles of the electrolytic medium.