Improving the Surface Finish of Diamond Turned Silicon with Magneto-Rheological Finishing

Abstract Single-point diamond turning is the most popular method for generating surfaces with micron accuracies. Residual turning marks and the diffraction pattern caused in diamond turning hinder the performance in the optical systems. Magneto-rheological finishing is based on magneto-rheological fluid, which consists of magnetic particles, non-magnetic abrasives and some additives in water or other carrier to polish the materials. Magneto-rheological finishing has capability to improve roughness, eliminate the micro cracks generated (sub surface damage) and reduce residual stresses induced during diamond turning process. The hybrid combination of single-point diamond turning and magneto-rheological finishing creates a deterministic process for manufacturing highly finished surfaces. In this paper, an attempt has been made to improve the surface finish of diamond turned silicon with magneto-rheological finishing. Further the effects of process parameters of Single Point Diamond Turning and Magneto-Rheological finishing process on the final surface finish is investigated.