Study on magnetorheological nano-polishing using low-frequency alternating magnetic field

With the development of electronics and optical industry, the high-efficiency ultra-precision polishing technologies of flat and curved surfaces are in high demand. The traditional magnetorheological polishing technology, using flexible polishing head, has the disadvantages of low polishing efficiency and small processing area. In this study, a novel tray-type magnetorheological polishing process using low-frequency alternating magnetic field excitation was developed to improve the efficiency of magnetorheological polishing for large surfaces and to make polishing magnetorheological cluster generate a cyclical fluctuation up and down, and then improve the cross-cutting effects of abrasives. With the developed excitation system, a large bowl-shaped varying magnetic field was generated in the working area, and the effects of current frequency, working gap, trough rotation speed, and workpiece rotation speed on the improvement rate of surface roughness and material removal rate were systematically investigated. A series of experiments were conducted on K9 glass specimens to verify the polishing performance. Experimental results show that the surface roughness of K9 glass was improved from 567.08 to 9.63 nm in 120 min.