Study on optimization of a NiP layer polishing process on magnetorheological finishing for metal substrate

Due to Metal mirror's low hardness, we coat a layer of nickel-phosphorus (NiP) layer on the surface and then polish NiP layer simpler through various methods. However, when using CeO₂ slurry in Magnetorheological Finishing(MRF), the NiP layer will appear "wise-tail" phenomenon. Based on the "double-edged circle" model, we analyze the shear force of the contact surface and optimize the polishing abrasive particles such as SiO₂. In this way, we could obtain a surface without "wise-tail" and the surface roughness reaches 1.897 nm in Ra. By orthogonal experiments, we optimize the process parametersts and certify the stability and linearity of the removal function.The experiment results prove that the MRF fluid compounded with SiO₂ could satisfy the requirements of NiP layer in magnetorheological machining.