I. Types of polishing powder
Polishing powder is usually composed of aluminum oxide, silicon oxide, zirconium oxide, cerium oxide and other ingredients. These materials have different hardness and different chemical properties in water, so each polishing powder has its specific application occasion. For example, the Mohs hardness of aluminum oxide and zirconium oxide is as high as 9, while cerium oxide and silicon oxide are 7, and the hardness of iron oxide is even lower. In particular, cerium oxide has a high chemical activity with silicate glass, and its hardness is moderate, so it is often widely used in the polishing process of glass products.
II. Basic requirements for polishing powder
(1) The particle size of the micro powder should be uniform and consistent and within the specified range;
(2) High purity is essential to ensure that there are no mechanical impurities;
(3) Good dispersibility helps to ensure uniform and efficient processing, and the suspension rate can be improved by adding a proper amount of dispersant;
(4) The powder particles should have a certain lattice morphology so that they can form sharp edges when broken, thereby improving polishing efficiency;
(5) Appropriate hardness and density, as well as good wettability and suspension with water, are all key characteristics of polishing powder. In addition, polishing powder with large particle size has stronger grinding force and is more suitable for harder materials. However, it should be noted that all polishing powders have certain distribution problems in particle size. The size of the average particle size or median diameter D50 mainly affects the polishing speed, while the particle size Dmax determines the polishing accuracy. Therefore, to achieve high-precision polishing effects, the particle size of the polishing powder must be strictly controlled. Ordinary polishing powder may have scratch problems due to the presence of large particles. Therefore, it is usually recommended to choose nano polishing powder with a narrow particle size distribution range (. At the same time, the finer the polishing powder, the brighter the polished material will be.
During the polishing process, the concentration of the slurry has a significant effect on the polishing speed. The higher the concentration, the higher the polishing speed. However, when using small-particle polishing powder, the slurry concentration needs to be appropriately reduced to ensure proper fluidity. It is generally recommended to control the slurry concentration within the range of 7-10%.
3. Selection of polishing mold
During the polishing process, it is crucial to choose a suitable polishing mold. Generally, it is recommended to use a polishing mold with a softer texture to ensure the quality of the polishing effect. It is worth noting that many polyurethane polishing pads are mixed with cerium oxide polishing powder, and the particle size of this polishing powder will directly affect the final polishing quality. degree. Of course, in addition to polishing molds with added polishing powder, there are also polishing molds without polishing powder such as sponge wheels and wool wheels to choose from.
IV. Indicators affecting the performance of polishing powder
The performance of polishing powder is affected by multiple indicators. First, the particle size of the polishing powder must be kept uniform and within the specified range to ensure the uniformity and efficiency of processing. Secondly, high purity is essential to prevent the influence of mechanical impurities on the polishing effect. In addition, good dispersibility, appropriate hardness and density, and good wettability and suspension with water are all important factors affecting the performance of polishing powder. At the same time, polishing powder with large particle size has stronger grinding force and is suitable for harder materials, but attention should be paid to the effect of particle size distribution on polishing speed and accuracy. Finally, the concentration of the slurry It will also affect the polishing speed and effect, especially when using small-particle polishing powder, the slurry concentration needs to be adjusted appropriately to maintain appropriate fluidity.
1. Powder particle size: Particle size and uniformity are crucial to polishing speed and precision. The mesh size of the sieve can control the powder particle size, while the average particle size reflects the overall level of the polishing powder particles.
2. Powder hardness: Powders with higher hardness have faster cutting effects, and adding grinding aids can also improve cutting effects. However, it should be noted that different application fields and processing technologies have different requirements for hardness.
3. Powder suspension: Good suspension is essential for polishing powder. Powder shape and particle size will affect its suspension. Nano-particle polishing powder performs better in this regard, so nano-polishing powder is often used for fine polishing.
4. Powder Crystal form: The powder is composed of agglomerated single crystal particles, which will separate during the polishing process, affecting the cutting performance, wear resistance and fluidity of the powder. Spherical particle polishing powder performs better in these aspects.
V. Polishing range segmentation:
Common fine polishing materials on the market include alumina polishing powder, cerium oxide polishing powder and silicon oxide polishing powder, etc., which play an important role in their respective application fields.
1. Application of alumina polishing powder:
Alumina polishing powder plays an important role in many fields. It is often used for polishing of stone, aluminum, stainless steel, cast iron, titanium alloy, as well as metallographic analysis, automotive paint mirror polishing, resin polishing and gemstone polishing. Its spherical particle characteristics make the particle size only 0.3um, thus ensuring excellent polishing effect.
2. Application of silica polishing powder:
Silica polishing powder, with a particle size of usually 50nm, is often used in the polishing process of artificial crystals, gemstones and metal products to repair their tiny flaws.
3. Application of cerium oxide polishing powder or polishing liquid: This kind of polishing powder or polishing liquid, the primary particle size is usually controlled at 20-30nm, and the secondary particle size is required to reach 0.2um, which is very suitable for polishing lenses, TV picture tubes, glasses, wafers and various optical components, optical fibers, art glass, electronic glass and flat glass.