INTRODUCTION
MTI-50-CSO 0.05 micron colloidal
silica (SiO2) slurry is a very unique polishing suspension
because it provides a chemical mechanical polishing
(CMP) action for materials such as crystals, ceramics,
composites and soft metals. It is stabilized at alkaline
pH values (typically >9.5). 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 electrochemcially attacks the surface
of a crystal, 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. alumina
or diamond). Polishing rates and surface finishes are
significantly better for crystals, ceramics, and minerals
as compared with straight mechanical abrasives such
as diamond. Thus the highest removal rates and the most
reliable action for removing both surface and subsurface
damage on crystals, ceramics, and minerals is via chemical
mechanical polishing with colloidal silica slurry.
|