Print-Through Correction on Lightweight Silicon Carbide Mirrors

Case Study Summary

Lightweighted silicon carbide mirrors are commonly used in space and large-aperture optical systems but are prone to print-through and quilting errors when polished using conventional techniques. This case study demonstrates how Magnetorheological Finishing (MRF) effectively corrects these errors without inducing additional deformation.

A 100 mm diameter silicon carbide mirror was processed on a Q-Flex 100 system using raster polishing with a 150 mm wheel and D10 MR fluid. Due to MRF’s low normal force and high lateral resolution, quilting artifacts were efficiently removed, improving surface RMS error from approximately 80.7 nm to 7.9 nm, representing a 10× improvement.

The results confirm MRF’s suitability for lightweight mirror applications where structural compliance and surface fidelity are critical. MRF provides a deterministic, non-deforming solution for achieving high-precision figure correction on advanced mirror substrates.