We all know that polishing of aluminium surface is mainly mechanical polishing and chemical polishing, and chemical polishing is divided into electrochemical polishing and chemical polishing. Three polishing processes are widely used, among which mechanical polishing is the application of physical methods to deal with workpieces, as the name implies, chemical polishing. Polishing effect has its own merits. We can see the characteristics of mechanical polishing and chemical polishing.
Mechanical polishing. Mechanical polishing is generally the operation of pressing the workpiece onto a rotating cloth wheel or other elastic wheel pre-coated with polishing paste. The essence of mechanical polishing is to use polishing wheels to smooth the tiny unevenness on the polished surface of the workpiece. Aluminum profiles can be polished by mechanical polishing to obtain a mirror-like surface whose luster varies with the polishing paste used. Electrolytic polishing takes the workpiece as an anode. In the process of electrolysis, the dissolution rate of the prominent part of the workpiece is faster than that of the low concave part. With the polishing process, the micro and macro concave parts of the workpiece surface can be leveled. This process can improve the micro-geometry of the metal surface and reduce the micro-structure of the metal surface. Roughness, aluminium profiles make the surface of parts bright.
Chemical polishing can be used in instrument manufacturing, aluminium mirror manufacturing, and decorative processing of other parts and coatings. Compared with electrolytic polishing, chemical polishing has the advantages of no additional power supply, processing parts with more complex shapes and high production efficiency. However, the surface quality of chemical polishing is generally slightly lower than that of electrolytic polishing. Polishing, solution adjustment and regeneration are also more difficult, often in the polishing process will precipitate harmful gases such as nitric oxide. In fact, this technology has also been solved. There are polishing reagents such as ht431 smokeless dicarboxylic acid chemical polishing Brightener on the market, which do not contain nitric acid and will not produce harmful yellow smoke.
In the electropolishing process, different from chemical polishing methods such as using ht431 smokeless dicarboxylic acid chemical polishing highlighter, it uses electrodes to react with the workpiece to treat the surface. The dense mucosa with high resistivity is formed on the surface of the anode. The micro-bulge part of the mucosa on the surface is smaller and the micro-concave part is thicker. Therefore, the micro-distribution of current density is uneven. The current density of the micro-bulge part is higher and dissolves faster, while the current density in the micro-concave part is lower and dissolves slower. In this way, the size of the micro-protruding part decreases rapidly and the size of the micro-concave part decreases slowly, so as to achieve the purpose of smoothness and brightness. In the chemical polishing process, either because of the formation of inhomogeneous passivation film on the micro-surface of metal or because of the formation of thick mucous film similar to that in the electropolishing process, the micro-protruding surface can be achieved. The dissolution rate of the outlet part is significantly higher than that of the micro-concave part, which reduces the micro-roughness of the part surface and makes the part surface brighter and smoother.
It can be seen that mechanical polishing and chemical polishing do have their own advantages. For chemical polishing, it does not need special processing equipment of mechanical polishing and electrochemical polishing, which reduces the cost of equipment. But to be realistic, the polishing effect of the latter two is really good. Specific choice depends on the strength of processing products and manufacturers.
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