The commonly used alloy aluminum 6061, 7075 and cast aluminum A356 have good coloring effects.
There is no necessary connection between die casting and anodizing.
There are many types of cast aluminum, and it is not necessary to choose silicon-aluminum alloys (cast aluminum is divided into Al-Si series, AL-Cu series, AL-Mg series, AL-Zn series, etc., as well as those mixed with rare earth elements). Even with silicon-aluminum alloys, anodizing is not impossible. Generally speaking, alloy aluminum contains more or less silicon elements, such as 6061 contains 0.4~0.8% silicon, 7075 contains 0.4% silicon, and such silicon content has little effect on alloy anodizing (by the way, copper content has little effect on aluminum alloy anodizing, but copper and manganese have a great impact on hard oxidation and porcelain oxidation). However, when the silicon content in the alloy is large (>7%), the anodizing of the alloy will have an effect. It is mainly reflected in the long time of oxidation, the film appears gray, etc., these problems can be solved through the process (such as using direct current, but pulse current oxidation), which requires surface treatment manufacturers to have certain technical capabilities. Therefore, cast aluminum≠ silicon-aluminum alloy ≠ cannot be anodized.
In addition, let's talk about color. The anodizing and coloring of aluminum alloys are two different processes, which are different from the bluing of steel. The bluing of steel is that the oxide film itself is blue, while the coloring is carried out immediately after anodizing, and the oxide film itself is colorless and transparent. The oxide film obtained by anodizing the aluminum alloy with sulfuric acid is the most suitable for dyeing, and now more organic dyes are used for coloring, and then the oxide film is sealed after coloring. In addition, there are also heavy metal salts electrolytically colored, but it is more difficult to dye red according to the landlord's requirements!
The process in which steel parts are chemically treated in a solution containing phosphoric acid to form a protective film on the surface of steel that is insoluble in water is called phosphating treatment!
It mainly has the following characteristics:
1. The surface of the phosphate film is gray or dark gray.
2. The phosphate film is filled, oiled or painted, and has good corrosion resistance under atmospheric conditions.
3. The adsorption capacity of the film layer is strong, and it is often used as the bottom layer of the coating.
4. The phosphate film has high electrical insulation.
5. After phosphating treatment, the mechanical properties, strength and magnetism of the raw metal are basically unchanged.
6. The phosphate film has good lubricating properties.
7. The surface of the nitriding parts can be protected with phosphate film.
8. The biggest feature of phosphate film is that it can obtain a protective film on the inner surface of steel and the steel surface with complex shapes.
9. The hardness and mechanical strength of the film layer have a certain degree of brittleness.
Passivation generally refers to: in order to improve the protective performance and decorative performance of the galvanized layer, the plated parts are prevented from being treated in the solution to form a film with high chemical stability on the surface. After passivation, it can improve the protective performance and surface gloss of the galvanized layer.
Oxidation is generally divided into: the oxidation of aluminum, aluminum alloy and steel parts, but the purpose that can be achieved and the solution used are different