What are the common surface treatment processes for aluminum alloys?

by:Zeyi     2021-07-24
Generally, aluminum alloys and aluminum profiles require surface treatment to meet the needs of different customers. Then, what are the common surface treatment processes for aluminum alloys? Common aluminum alloy surface treatments include spraying, anodizing, sandblasting, passivation, polishing, coloring and oxide film treatment, etc., as follows:    1. Spraying: used for external protection and decoration of equipment, usually on the basis of oxidation get on. Aluminum parts should be pre-treated before painting to make the coating and the workpiece bond firmly. Generally, there are three methods: phosphating (phosphate method), chromizing (chromium-free chromizing), and chemical oxidation.  2. Anodizing: It is the process of plating a thin layer of other metals or alloys on the surface of certain metals using the principle of electrolysis. Brush plating is used for partial plating or repair. Barrel plating is used for small parts such as fasteners, washers and pins. Through electroplating, it is possible to obtain decorative protective and various functional surface layers on mechanical products, and to repair worn and processed workpieces. The electroplating solution includes acidic, alkaline, and acidic and neutral solutions with chromium mixture. No matter what plating method is used, the plating tanks and hangers that are in contact with the products to be plated and the plating solution should have a certain degree of generality. Sex.  3. Sandblasting is mainly used for surface cleaning. Sandblasting before painting (painting or plastic spraying) can increase the surface roughness and contribute to the improvement of adhesion to a certain extent, but the contribution is limited. It is not as good as the pretreatment of chemical coating.  4. Passivation: Passivation is a method to transform the metal surface into a state that is not easy to be oxidized and delay the corrosion rate of the metal.  A kind of active metal or alloy, in which the chemical activity is greatly reduced, and the phenomenon of becoming a noble metal is called passivation. If the corrosion product generated by the metal due to the action of the medium has a dense structure and forms a layer of film (often invisible), which covers the surface of the metal closely, the surface state of the metal is changed, and the electrode potential of the metal is greatly increased. Jump in the positive direction and become a passive state for corrosion resistance. For example, the standard potential of FeFe++ is -0.44V, and it jumps to +0.5~1V after passivation, and it shows corrosion-resistant precious metal performance. This film is called passivation film.   5. Chemical polishing: Chemical polishing is a chemical processing method that uses the selective self-dissolution of aluminum and aluminum alloys in acid or alkaline electrolyte solutions to level and polish the surface of the year to reduce its surface roughness and PH. This polishing method has the advantages of simple equipment, no power supply, no limitation on the size of the part, high polishing speed and low processing cost. The purity of aluminum and aluminum alloys has a great influence on the quality of chemical polishing. The higher its purity, the better the polishing quality, and vice versa.  6. u200bu200bColoring: There are two main processes for coloring aluminum: one is aluminum oxidation coloring process, and the other is aluminum electrophoresis coloring process. Various colors are formed on the oxide film to meet certain usage requirements, such as black for optical instrument parts and golden yellow for commemorative medals. 7.1 Chemical oxidation: The oxide film is thin, with a thickness of about 0.5-4 microns, and is porous, soft, and has good adsorption properties. It can be used as the bottom layer of organic coatings, but its wear resistance and corrosion resistance are not as good as anodized oxidation Film;    aluminum and aluminum alloy chemical oxidation process can be divided into two categories: alkaline oxidation and acid oxidation according to the nature of the solution.  According to the nature of the film, it can be divided into: oxide film, phosphate film, chromate film, chromic acid-phosphate film.  7.2. Electrochemical oxidation, aluminum and aluminum alloy chemical oxidation treatment equipment is simple, easy to operate, high production efficiency, does not consume electricity, has a wide range of applications, and is not limited by the size and shape of the parts. The thickness of the oxide film is about 5-20 microns (the thickness of the hard anodized film can reach 60-200 microns). It has high hardness, good heat resistance and insulation, and its corrosion resistance is higher than that of the chemical oxide film. It is porous and very Good adsorption capacity.
To live up to our responsibilities to serve and enhance the communities in which Zeyi Aluminum Co., Ltd. works and lives and the society on which we depend.
We believe our ability can raise a giant wave of innovation among the field of custom aluminium extrusion.
The major classifications of are aluminum window profile manufacturers, aluminum extrusion rail, aluminum window profile manufacturers and aluminum extrusion rail machines.
aluminum window profile manufacturers needs not be tedious anymore with the application of . So getting the right custom aluminium extrusion can drastically promote aluminum extrusion rail.
In business, custom aluminium extrusion means cultivating brand loyalty; once someone is working with a product or using a service, they are more likely to commit to paying for Zeyi again.
Custom message
Chat Online 编辑模式下无法使用
Chat Online inputting...