Patent ID: 8357287

Claim:
A method of micropolishing a surface of a non-ferrous metal workpiece, comprising: immersing a surface of a non-ferrous metal workpiece in a bath of an aqueous electrolyte solution including a concentration of citric acid in the range of about 1.6 g/L to about 780 g/L and a concentration of ammonium bifluoride in the range of about 2 g/L to about 120 g/L and having no more than about 3.35 g/L of a strong acid; controlling the temperature of the bath to be between the freezing point and the boiling point of the solution; continuing the immersion of the surface in the bath until the finish of the surface is smoother than prior to immersion in the bath; and removing the surface from the bath prior to causing a substantial change in the size or geometric shape of the workpiece.