Factors Influencing Material Removal And Surface Finish Of The Polishing Of Silica Glasses

摘要

The polishing process is ancient form of material processing that has changed little in form over thousands of years. Even with all of the experience that the human race has gained on the subject, the underlying mechanism that promotes polishing still lies in the realm of theory. Of the existing theories available, each falls into one of two broad categories, chemical or mechanical removal mechanisms, or a combination of both. Effects of polishing pressure and velocity on material removal rate were analyzed. A novel method of controlling the polishing load will also be provided. Additionally, this work quantifies some of the factors that influence polishing, and then correlate the results to polishing theory. Specifically, abrasive polishing particle size and concentration, and abrasive polishing slurry pH were variables in a broad range of experiments, with other influencing factors kept as consistent as possible. The effects of pH were analyzed for interaction with the entire polishing system, as well as for effects on the polishing workpiece only. Silica materials were used as a baseline, and are polished on a synthetic optical polishing pitch with ceria (cerium oxide) abrasive particles. Finally, the experimental results will provide justification for a combined chemical- mechanical material removal model and form the basis of future work on more advanced materials like glass-ceramics and ultra low expansion glasses.