Pace Technologies, CMP-1005-64, Chemicals Alumina-Silica Polishing Slurry (1/2 gallon)Application:The most efficient application is to initially wet the polishing cloth with Siamat Colloidal Silica and then to slowly drip or spray the suspension onto the polishing clothIt is recommended that water be applied continuously to the polishing cloth for 10-15 seconds prior to completion of the polishing step. This aids in removing the fine particles which may be electrostatically attracted to the specimen surface.Colloidal silica is a very unique polishing suspension because it provides a chemical mechanical polishing (CMP) action for materials such as ceramics, composites and soft metals. Colloidal silica has particle size distribution between 0.05µm and 0.07µm and is stabilized at alkaline pH values (typically >9.5).Ceramics and Minerals - At higher pH values, colloidal silica is held in nearly perfect suspension by the electrochemical repulsive forces of the fine particles themselves. This chemical balance electrochemically attacks the surface of a ceramic or mineral surface to form a thin reacted layer on the specimen surface. This reacted layer can then be removed via the mechanical action of the polishing cloth or another abrasive (e.g. dia-mond). Polishing rates and surface finishes are significantly better for ceramics and minerals as compared with straight mechanical abrasives such as dia-mond. Thus the highest removal rates and the most reliable action for removing both surface and subsurface damage on ceramics and minerals is via chemical mechanical polishing with colloidal silica.As with other exothermic chemical reactions, the chemical contribution can be enhanced by increasing the temperature of the polishing action. This can be accomplished by increasing the polishing pressure which increases the friction between the polishing cloth, colloidal silica and the specimen.Cleaning of the surface is best accomplished by running water on the surface for the final 10-15 seconds of the polishing cycle and then immediately rinsing the specimen surface with water. This allows the cloth to mechanically remove the reacted layer and any residual colloidal silica.