Abstract: To improve the efficient of Magnetorheological polishing, in this work, A planar magnetorheological polishing method with Halbach array excitation is developed. The 2D and 3D magnetic field distribution and force distribution characteristics of magnetic particles of different excitation modes are compared. It is proved that Halbach array has excellent excitation performance, efficient planar magnetorheological polishing can be realized. The morphology characteristics, polishing pressure and mark distribution, magnetorheological polishing performance, surface roughness and morphology evolutions with time under different excitation modes are described by comparison experiments. The mechanism of efficient planar magnetorheological polishing by Halbach array excitation is revealed. The polishing performance results show the removal rate of K9 optic glass polished by N35 Halbach array can reach 1.38 mm³/min, which is 4.4 times of permanent yoke and 6.9 times of N-S array. The ultra-smooth surface with surface roughness less than Ra 1 nm can be obtained after 30 min polishing. The Halbach array has excellent performance and flexible configuration, which greatly improves the efficiency of magnetorheological polishing, and has reference significance for other magnetorheological processes and other magnetic field assisted machining processes.

Key words: magnetorheological polishing fluid, magnetorheological polishing, Halbach array, magnetic field, K9 optic glass