White corundum is made from high-quality aluminum oxide powder and smelted at a high temperature of more than two thousand degrees. It has high purity, good self-sharpening, acid and alkali corrosion resistance, high temperature resistance, and stable thermal performance. Its hardness is slightly higher than that of brown corundum. The toughness is slightly lower, the grinding ability is strong, the calorific value is small, and the efficiency is high. High hardness, dense particles, good roundness of single particles, pure white color, no impurities. to ensure the color and transparency of the wear-resistant layer or wear-resistant paper.
The particle size distribution is uniform and concentrated, and the shape of the single particles is consistent. The minimum amount of use can achieve the maximum wear resistance.
Five methods commonly used when white corundum is used as a polishing material:
1. Fluid polishing: Fluid polishing relies on high-speed flowing liquid and the white corundum sand particles carried by it to wash the surface of the workpiece to achieve the purpose of polishing.
Commonly used methods are: emery jet processing, hydrodynamic grinding processing and so on. The hydrodynamic grinding is driven by hydraulic pressure, so that the liquid medium carrying the abrasive grains of white corundum flows back and forth across the surface of the workpiece through the sandblasting gun at high speed. The liquid medium is mainly made of special compounds with good fluidity under lower pressure and mixed with white corundum powder.
2. Mechanical polishing: Mechanical polishing refers to a polishing method that uses plastic deformation on the surface of the cutting material to remove the polished protrusions to obtain a smooth surface. Generally, oilstone strips, wool wheels, sandpaper, abrasive belts, nylon wheels, etc. are used. Manual operation is the main task. For special parts such as the surface of the revolving body. auxiliary tools such as turntables can be used. For high surface quality requirements, the method of ultra-precision polishing can be used.
3. Electrolytic polishing: The basic principle of electrolytic polishing is the same as that of chemical polishing. namely 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 macro leveling and micro leveling.
4. 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. so as to obtain a smooth surface. The main advantage of this method is that it does not require complex 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. and the proportion of white corundum sand in the polishing liquid is very important.
5. Magnetic grinding and polishing: Magnetic grinding and polishing uses magnetic green silicon carbide to form white corundum sand under the action of a magnetic field. and the polishing sheet grinds the workpiece. This method has high processing efficiency, good quality, easy control of processing conditions and good working conditions.