1. The key to the operation of the polishing machine is to try to achieve a polishing rate in order to remove the damaged layer generated during polishing as soon as possible. At the same time, the polished damage layer should not affect the later observed tissue, that is, it will not cause false tissue. The former requires the use of a coarser abrasive to ensure a greater polishing rate to remove the polished damage layer, but the polishing damage layer is also deeper; the latter requires the use of fine materials to make the polishing damage layer shallower, but the polishing rate low.
2. The solution to this contradiction is to divide the polishing into two stages. The purpose of rough polishing is to remove the polished damage layer. This stage should have a large polishing rate. The surface damage caused by rough polishing is a secondary consideration, but it should also be as small as possible; followed by fine polishing (or final polishing). The purpose is to remove the surface damage caused by rough polishing, so that the polishing damage is minimized.
3. When polishing with a polishing machine, the grinding surface of the sample and the polishing disc must be pressed parallel and lightly on the polishing disc, taking care to prevent the sample from flying out and new grinding marks due to excessive pressure. At the same time, the sample should also be rotated and moved back and forth along the radius of the turntable to avoid local wear of the polishing fabric too quickly. During the polishing process, a fine powder suspension must be continuously added to keep the polishing fabric at a certain humidity.