Smoothing technique for perforated parts by means of magnetically circulating particles

A polishing system, comprising:

• a workpiece holder comprising a rod configured to axially support a perforated workpiece, the perforated workpiece separated from the rod by a plurality of wires distributed about the rod and extending axially along the rod, the plurality of wires thereby spacing the perforated workpiece away from the rod;
• a pole tip configured to be positioned adjacent to and extending over at least a portion of the workpiece, the pole tip configured to provide a magnetic field that extends from the pole tip to the rod through the perforated workpiece, where the magnetic field supports a mixture comprising magnetic particles, abrasive and lubricant positioned between the pole tip and the workpiece;
• and
• a workpiece drive configured to rotate the rod, where rotation the perforated workpiece by the rod polishes external, internal, and sidewall surfaces of the perforated workpiece by circulation of the mixture.

A method, comprising:

• supporting a perforated workpiece on a rod that extends axially through the perforated workpiece, the rod comprising a ferromagnetic core covered by nonferromagnetic material, the ferromagnetic core having a diameter greater than end openings of the perforated workpiece, the perforated workpiece supported by a plurality of wires extending axially along the rod, the plurality of wires distributed about the rod thereby spacing the perforated workpiece away from the rod;
• positioning an outer surface of a turning wheel against an external surface of the perforated workpiece, where the outer surface comprises a mixture of ferromagnetic particles, abrasive particles, and lubricant and the external surface of the perforated workpiece is held against the outer surface, and the spacing provided by the plurality of wires allowing circulation of the mixture of ferromagnetic particles, abrasive particles, and lubricant about the external surface, an internal surface, and an sidewalls through perforations of the perforated workpiece;
• and
• rotating the perforated workpiece by rotating the turning wheel, where the external and internal surfaces and sidewall surfaces of the perforated workpiece are polished by circulation of the mixture during rotation of the perforated workpiece.