Published in： 2021-01-21 14:02:21, published via： cyanbat | clicks: 0 | Information Sources：
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Metal grinding and polishing technology
1. Mechanical polishing
Mechanical polishing is a polishing method that relies on cutting and plastic deformation of the material surface to remove the polished protrusions to obtain a smooth surface. Generally, oil stone sticks, wool wheels, sandpaper, etc. are used, and manual operations are the main method. Special parts such as the surface of the rotating body can be used. Use the turntable and other auxiliary tools, and the ultra-precision polishing method can be used if the surface quality is high. Ultra-precision polishing is the use of special abrasive tools, which are pressed against the processed surface of the workpiece in a polishing liquid containing abrasives for high-speed rotation. The surface roughness of Ra0.008μm can be achieved by this technology, which is the highest among various polishing methods. Optical lens molds often use this method.
2. Chemical polishing
Chemical polishing is to make the surface microscopic convex part of the material in the chemical medium dissolve preferentially than the concave part, thereby obtaining a smooth surface. The main advantage of this method is that it does not require complicated equipment, can polish workpieces with complex shapes, and can polish many workpieces at the same time, with high efficiency. The core problem of chemical polishing is the preparation of polishing liquid. The surface roughness obtained by chemical polishing is generally several 10 μm.
3. Electrolytic polishing
The basic principle of electrolytic polishing is the same as that of chemical polishing, that is, by selectively dissolving tiny protrusions on the surface of the material to make the surface smooth. Compared with chemical polishing, the effect of cathode reaction can be eliminated, and the effect is better. The electrochemical polishing process is divided into two steps: (1) Macroscopic leveling The dissolved products diffuse into the electrolyte, and the geometric roughness of the material surface decreases, Ra>1μm. (2) Low-light leveling and anode polarization, improving surface brightness, Ra<1μm.