Fluid developments for Magnetorheological Finishing of Silicon Carbide

High precision, lightweight optics are required for numerous seekers, aircraft, and satellites programs. Current system demands require that the optics operate in a variety of conditions and in wavelengths from the visible to very long wave IR. This translates into a need for large (up to 30 cm) mirrors in difficult to manufacture materials, e.g., SiC, with surface requirements that meet or exceed surface figure of 1/60-wave RMS and surface roughness of < 20 angstroms. Current manufacturing technologies cannot affordably produce these components. Magnetorheological Finishing (MRF) is a production-proven technology for the economic production of precision optics, including difficult to manufacture shapes such as aspheres. Although MRF can polish SiC lightweight mirrors with high precision and convergence rates, more work is required to optimize the MRF technology to be production ready for these next-generation materials. This proposal will culminate in an MR finishing process, designed specifically for SiC, and enable a turn-key solution for the rapid fabrication of high precision SiC optics.