Magnesium aluminum alloy die casting factory electroplating

In industrial production, aluminum alloy die castings are widely used, and aluminum alloy die castings require special electroplating pretreatment, including four important processes such as oil, acid etching, chemical plating or displacement plating, and pre-plating. Let’s work with the editor of CYANBAT, a magnesium-aluminum alloy die-casting factory, to understand the common methods of electroplating aluminum alloy die-castings.

Aluminum phosphating: The effects of accelerators, fluoride, Mn2+, Ni2+, Zn2+, PO4; and Fe2+ on the phosphating process of aluminum are studied in detail by using SEM, XRD, potential-time curve, film weight change and other methods. Studies have shown that guanidine nitrate has the characteristics of good water solubility, low dosage, and rapid film formation. It is an effective accelerator for aluminum phosphating: fluoride can promote film formation, increase film weight, and refine grain; Mn2+ and Ni2+ can be obvious Refine the grains to make the phosphating film uniform and compact and improve the appearance of the phosphating film; when the Zn2+ concentration is low, the film cannot be formed or the film formation is poor. As the Zn2+ concentration increases, the film weight increases and the O4 content increases the weight of the phosphate film The impact is greater, increase PO4. The content increases the weight of the phosphating film.

Environmentally friendly chemical polishing for aluminum and aluminum alloys. It is determined to develop a new environmentally friendly chemical polishing technology based on phosphoric acid-sulfuric acid as the base fluid. This technology must achieve zero emission of NOx and overcome the quality shortcomings of similar technologies in the past. The key to the new skill is to add some special compounds in the base fluid to replace nitric acid. For this reason, the primary need is to analyze the three-acid chemical polishing process of aluminum, especially the key points to study the role of nitric acid. The primary role of nitric acid in aluminum chemical polishing is to suppress pitting corrosion and improve polishing brightness. Combined with the chemical polishing experiment in simple phosphoric acid-sulfuric acid, it is thought that the special substances added in phosphoric acid-sulfuric acid should suppress pitting corrosion and slow down overall corrosion. At the same time, it is necessary to have a better smoothing and brightening effect.

Electrochemical surface strengthening treatment of aluminum and its alloys. The process, function, description, composition and structure of the anodic oxidation and accumulation of aluminum and its alloys in a neutral system to form a ceramic-like amorphous composite conversion coating have begun to discuss the film formation process and mechanism of the coating. The results of the process study indicate that in the Na_2WO_4 neutral mixing system, the concentration of the film forming promoter is controlled to be 2.5—3.0g/l, the concentration of the complexing film agent is 1.5—3.0g/l, and the concentration of Na_2WO_4 is 0.5—0.8 g/l, peak current density is 6—12A/dm—2, weak mixing, a complete, uniform, and good-gloss gray series inorganic non-metallic film can be obtained. The thickness of the film is 5-10μm, the microhardness is 300-540HV, and the corrosion resistance is excellent. The neutral system has good adaptability to aluminum alloys, and can form a good film on various series of aluminum alloys such as rust-proof aluminum and forged aluminum.