What are the pre-process operations before metal surface treatment
Date:2020-07-13 17:15Views:
What are the pre-process operations before metal surface treatment
Lambwang metal surface treatment, pre-baking treatment is intended to obtain an outstanding coating, because the above stamped parts will have grease, oxide scale, dust, rust and corrosives during the production, processing transfer and storage On the surface, if it is not removed, it will directly affect the function and appearance of the coating film, so the previous treatment occupies an important position in the coating process.
The oxidation color of aluminum alloy generally has the nature and sky blue. Anodizing is carried out under the condition of high-voltage electricity, it is an electrochemical reaction process; conductive oxidation does not need to be energized, but only needs to be soaked in the medicine, it is a pure chemical reaction. The time required for anodizing is very long, often several tens of minutes, while conductive oxidation requires only a few tens of seconds. Electroplating is the process of depositing a metal or alloy on the surface of a workpiece using an electrolytic method to form a uniform, fine, and excellent binding metal layer, which is called electroplating. A brief understanding is the physical or chemical changes or combination.
We generally use the plating process for the following purposes: anti-corrosion, protective decoration, and anti-wear. The so-called phosphating film treatment on the metal surface refers to cleaning the metal surface under specific conditions, allowing the metal to touch the distributed phosphating solution, and undergoing a chemical or electrochemical reaction to form a hardly soluble water on the metal surface Phosphate coating. Its physical and chemical properties can be used for various purposes in industrialization planning, which is mainly used for coating the bottom layer and cold plastic deformation processing. The phosphating film for drawing deformation should have the following conditions: crystalline porosity and appropriate thickness.
If the phosphating film is too finely crystallized, it will affect the smooth reaction and reduce the smooth function; the film is too thin to be loaded and deformed, which reduces the life of the die and has no smooth surface, which seriously affects the cold forging process. Generally speaking, there are two explanations of surface treatment in China. One is the surface treatment in a broad sense. The surface treatment agent includes many physical and chemical methods including pretreatment, electroplating, painting, chemical oxidation, and thermal spraying. A kind of surface treatment in a narrow sense, that is, only including sandblasting, polishing, etc. that we often say the pre-treatment part.
Depending on the metal surface with different degrees of oxidation, different treatment methods should be used. For thin oxide layer, solvent cleaning, mechanical treatment and chemical treatment can be used, or chemical treatment is directly selected. For severely oxidized metal surfaces, because the oxide layer is thick, it is assumed that solvent cleaning and chemical treatment are directly used, not only incomplete treatment It will also spoil a lot of cleaning agents and chemicals, first choose mechanical treatment.