The geometric shape of magnets was modified to improve surface planarity and polishing efficiency in magnetorheological planarization. Two modified permanent magnetic yokes and a magnetic brick were used as excitation units of magnetic field. Stress analysis indicated that the polishing stress of the horizontal magnetic yoke was smaller than that of the brick magnet, but greater than that of the sloping yoke. The performances of MR planarizations, including removal rate, roughness, and planarity, of the three magnetic sources were also compared...
