At present, there are several useful ways of lapping of silicon carbide products:
1 Mechanical polishing
Mechanical polishing is to rely on cutting, the plastic deformation of the surface to remove the polished polished surface and get a smooth surface of the polishing method, the general use of oil stone, wool wheel, sandpaper, etc., to manual operation, special parts such as the surface of the rotor The use of turntable and other auxiliary tools, high surface quality requirements can be used ultra-fine grinding method. Ultra-fine grinding is the use of special abrasive, grinding in the abrasive containing the material, the workpiece in the workpiece surface, for high-speed rotary motion. Using this technology can achieve Ra0.008μm surface roughness, is the highest of a variety of polishing methods. Optical lens mold often use this method.
2 Chemical polishing
Chemical polishing is to let the material in the chemical medium in the surface of the micro-protruding part of the concave part of the priority to dissolve, resulting in a smooth surface. The main advantage of this method is that without complex equipment, you can polish the shape of the complex parts, you can polish a lot of workpieces with high efficiency. The core problem of chemical polishing is the preparation of the polishing solution. The surface roughness obtained by chemical polishing is generally 10 m.
3 electrolytic polishing
The basic principle of electrolytic polishing and chemical polishing is the same, that is, by selectively dissolving the surface of the material slightly protruding part of the surface smooth. Compared with the chemical polishing, can eliminate the impact of the cathode reaction, the effect is better. Electrochemical polishing process is divided into two steps: (1) macroscopic leveling dissolution products to the electrolyte diffusion, the material surface roughness decreased, Ra> 1μm. (2) Smoothing Anodic polarization, surface brightness increased, Ra <1μm.
4 ultrasonic polishing
Place the workpiece in the abrasive suspension and place it in the ultrasonic field together, relying on the oscillating effect of the ultrasonic wave to grind the abrasive on the surface of the workpiece. Ultrasonic processing of small macro, will not cause the workpiece deformation, but the tooling production and installation more difficult. Ultrasonic processing can be combined with chemical or electrochemical methods. In the solution corrosion, electrolysis, and then add the ultrasonic vibration stirring solution, the workpiece surface dissolution products from the surface near the corrosion or electrolyte uniform; ultrasonic cavitation in the liquid can also inhibit the corrosion process, conducive to the surface of the light
5 Fluid polishing
Fluid polishing is to rely on high-speed flow of liquid and carry the abrasive particles to wash the surface of the workpiece to achieve the purpose of polishing. Common methods are: abrasive jet processing, liquid jet processing, hydrodynamic grinding and so on. Fluid power grinding is driven by the hydraulic, so that the liquid medium carrying abrasive high-speed reciprocating flow through the workpiece surface. The medium is mainly made with a special compound (polymer-like substance) with good flowability at lower pressure and mixed with abrasive. The abrasive can be made of silicon carbide powder.
6 Magnetic grinding and polishing
Magnetic grinding and polishing is the use of magnetic abrasive in the magnetic field under the action of the formation of abrasive brush, the workpiece grinding. This method of processing is with high efficiency, good quality, and easy to control the processing conditions, good working conditions. With the appropriate abrasive, the surface roughness can reach Ra0.1μm.
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