A comparative study on magnetorheological planarization using modified magnetic yokes and brick magnet

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. The results showed that the sloping yoke produced the lowest surface finish of 0.6\ua0nm in R and the best planarity of 0.7\ua0μm in PV, and the brick magnet provided the highest removal efficiency