The three-point eccentric magnetorheological polishing technology for hard brittle alumina ceramics

Abstract. This work presents the design of a pressurised three-point eccentric magnetorheological polishing (MRP) device, for alumina ceramics' hard and brittle characteristics, and a carrier disc magnetic field generator and a single closed-loop uniform magnetic field generator for a more uniform and increased magnetic field distribution. When compared with the traditional gap type, this device considerably enhances polishing efficiency. This apparatus has also been used to explore the mechanism of MRP. Static magnetic field simulations were conducted, and the fundamentals of the three-point eccentric magnetorheological process were addressed. Alumina ceramics were polished with a three-point eccentric wheel MRP equipment. Polishing tests were conducted to explore the effects of rotational speed, working pressure, abrasive type, abrasive particle size and polishing duration on polishing properties, and optimised polishing parameters were established. The surface roughness (Ra) of the samples was dramatically reduced from 500 to 22.41 nm using the three-point eccentric MRP device. The pit markings on the alumina ceramics' surface vanished after polishing. Therefore, the approach has considerable polishing potential for hard and brittle materials that can be nanofabricated with minimal surface sub-damage.