Slurry particle size evolution during the polishing of optical glass.

The particle size distribution of aqueous metal-oxide slurries can evolve during the polishing of optical glass in response to changes in mechanical and chemical process factors. The size-evolution phenomenon and its consequences were systematically studied in a planar continuous-polishing process. The concurrent application of electrokinetic techniques to characterize common optical shop materials has contributed new insight into the nature of silicate glass polishing by demonstrating the pivotal role of fluid chemistry, particularly pH, in maintaining electrokinetically favorable conditions for a welldispersed polishing agent. According to the proposed slurry-charge-control effect, a well-dispersed polishing agent is the key to obtaining the smoothest possible glass surfaces, especially when a recirculated slurry is used.