High-precision optical glass is commonly used to make invisible radar search mirrors, surveillance satellite camera lenses, high-speed aircraft windows, and optical lenses, prisms and other ultra-precision parts in laser emitting devices. The application of high-precision optical glass requires very high requirements for polishing powder in optical glass polishing. The basic requirements for optical glass polishing powder are summarized below (1) The particle size of the fine powder is fine and uniform, within the allowable range (2) has high purity and does not contain other mechanical impurities; (3) has very good dispersibility to ensure high efficiency and uniformity in the processing process, and appropriate dispersing agents can be added to increase the suspension rate; (4) fine powder It needs to have a certain crystal lattice shape, and form sharp edges and corners when broken to improve polishing efficiency; (5) has proper density and hardness, and has good wettability and suspension with water. Polishing powder needs to be mixed with water. The larger the polishing powder, the greater the grinding force, and the more suitable it is for harder materials. It should be noted that the particle size of all polishing powders has a distribution problem. The average particle size or the median diameter D50 only determines It determines the polishing speed, and the maximum particle size Dmax determines the polishing accuracy. Therefore, in order to obtain high-precision requirements, the maximum particle size of the polishing powder must be controlled. The real hardness of the polishing powder is related to the material. For example, the hardness of the alumina type is about 9 on the Mohs scale, and all kinds of alumina are similar. However, different aluminas have different hardness. Due to the different sintering temperature, the strength of the agglomerate is different, so there will be a feeling of different hardness during use, and the grinding rate and wear resistance of the product will be different. This requires experienced production plants to control according to different materials. The concentration of the slurry in the polishing process determines the polishing speed, the greater the concentration, the higher the polishing speed. When using small-particle polishing powder, the slurry concentration should be appropriately adjusted to obtain suitable fluidity. Generally, it is recommended to be 7-10%.
Global Glass Network (www.glass.cn) News Editorial Department