Magnetorheological (MR) Jet Finishing Technology

Abstract

One suitable way to polish optics of complex shapes is by using a jet of abrasive fluid. In doing so, the energy required for polishing is supplied by the radial spread of the jet, which impinges upon a surface to be polished. Generally, the jet instability results in a non-deterministic polishing process. A method of jet stabilization has been proposed, developed, and demonstrated whereby the round jet of magnetorheological (MR) fluid is magnetized by an axial magnetic field as it flows out of the nozzle. It has been experimentally shown that in this case a stable and reproducible material removal function can be achieved at a distance of several tens of centimeters from the nozzle. At the same time, the interferometrically derived distribution of material removal for the MR jet coincides well with the distribution of the fluid power density calculated using CFD modeling. Polishing results support the assertion that the MR jet finishing process may produce high precision surfaces on glasses and single crystals.