Performance Evaluation of Rotational-Magnetorheological Glass-Ceramic Polishing (R-MRGP) Process Setups

Ultrafine glass-ceramic polishing is very challenging due to structural inconsistencies, chemical inhomogeneity and high stiffness. In the modern optics sectors, glass-ceramics are extensively used. In the present study, two different experimental setups of rotational-magnetorheological glass-ceramic polishing (R-MRGP) process are used to super-finish the complex freeform curved profiles of the glass-ceramic workpiece. After polishing, the performance of both R-MRGP process setups is compared in terms of uniformity in surface roughness, surface reflectance characteristics, surface topographical images and material removal rate (MRR). Further, magnetostatics fluid-flow analysis is performed for both R-MRGP process setups to study the distributions of magnetic flux density (MFD), axial velocity and shear stress along the glass-ceramic profile. This finite element analysis (FEA) helps in recognizing the polishing capability of R-MRGP process setups. In the current study, finishing force analysis is also performed to develop a theoretical model for predicting and comparing the obtained MRR in both R-MRGP process setups. The final outcome demonstrates that the workpiece has an excellent surface quality, with a minimum achieved roughness of 1.91 nm after using the R-MRGP process setup-II. The versatility of the R-MRGP process makes it a viable option for ultra-precision polishing of glass-ceramics.

Automated summary

This study investigates the super-finishing of glass-ceramic workpieces using rotational-magnetorheological glass-ceramic polishing (R-MRGP) process. Two different experimental setups are compared in terms of surface roughness, reflectance characteristics, topographical images, and material removal rate (MRR). Finite element analysis (FEA) is used to analyze the magnetic flux density, axial velocity, and shear stress. The study concludes that R-MRGP is a viable option for ultra-precision polishing of glass-ceramics, achieving excellent surface quality.