Model of Magnetorheological Finishing

Abstract

The technology of finishing for optics, ceramics, and semiconductors is one of the most promising uses of the magnetorheological effect. It perfectly coupled with computer control, allowing in quantity production the unique accuracy and quality of a polished surface to be achieved. The polishing process may appear as follows. A part rotating on the spindle is brought into contact with a magnetorheological polishing (MRP) fluid which is set in motion by the moving wall. In the region where the part and the MRP fluid are brought into contact, the applied magnetic field creates the conditions necessary for the material removal from the part surface. The material removal takes place in a certain region contacting the surface of the part which can be called the polishing spot or zone. The polishing process comes to the program-simulated movement of the polishing spot over the part surface. The mechanism of the material removal in the contact zone is considered as a process governed by the particularities of the Bingham flow in the contact zone. The problem like the hydrodynamic theory of lubrication is treated for plastic film. As this takes place, the shear stresses distribution in the film is obtained from the experimental measurements of the pressure distribution in the contact spot. Reasonable correlation between calculated and experimental magnitudes of the material removal rate for glass polishing lends support to the validity of the approach.