Investigation of MRR and surface characterization using plasma process

Fused silica glass, in particular, offers a broad range of applications in optics. The present study investigates fused silica samples using non-conventional medium-pressure plasma polishing at optimum machining parameters. The polishing parameters, i.e. gas composition (He: (SF6+O2)) of 90:10, pressure ratio (SF6:O2) of 1:1, total pressure of plasma chamber of 5 mbar, and radio-frequency (RF) power of 80 W have been obtained at optimum parametric conditions. The highest material removal rate of 100.36 × 10−3 mm3/min is achieved at optimized process conditions. Even though the surface finish is slightly degraded from 0.28 µm to 0.30 µm, without any surface contamination as analyzed by the 3D optical profiler and Energy-Dispersive X-ray (EDX). Moreover, EDX analysis reveals the presence of fluorine elements after plasma processing, confirming the plasma's interaction with the substrate. Furthermore, Raman spectroscopy results show a maximum 13% reduction in damaged and strained layers after plasma processing on the machined surface..