The development history of aluminum alloy die-casting

The development history of aluminum alloy die-casting

The history of die casting always varies. According to the relevant articles, the first thing is die cast lead. In 1822, William Joch (WillamChurch) built a casting machine with a daily output of 12,000 to 20,000 words. More than 20 years later, The J.J.Sturgiss (J.J.Sturgiss) designed and created the first manual piston hot chamber die casting machine, and was patented in the United States. In 1885, Mergenseler studied the previous patent and invented the die casting machine. By the 1860s for zinc alloy die-casting parts production. Die-casting is widely used in industrial production only at the beginning of the last century. 1905 Doppler (H.H.Doehler) successfully developed for industrial production of die casting machine, die casting zinc, tin, copper alloy casting. Wagner (Wagner) then designed a gooseneck air pressure die casting machine for the production of aluminum alloy die casting.

 product use Aluminum alloy die-casting products are mainly used in electronics, automobile, motor, home appliances and some communication industries, some high performance, high precision, high toughness of high quality aluminum alloy products are also used in large aircraft, ships and other high requirements. The main use is still on the parts of some devices.

The characteristics of die casting 1. Wide range of die-casting 2. High casting dimensional precision, low surface roughness 3. High productivity 4

Die-casting surface treatment of aluminum alloy 1. Aluminum phosphorylation The effects of SEM, XRD, potential time curve, Mn 2 +, Ni2 +, Zn 2 +, PO4, Fe2 + and membrane weight change. The study shows that guanidine nitrate is characterized by good water solubility, low dosage and rapid film formation, and is an effective promoter of aluminum phosphorization: fluoride can promote the film formation, increase the film weight, and refine the grain; Mn 2 + and Ni2 + can significantly refine the grains, compact and improve the appearance of phosphating film; when Zn 2 + concentration is low, no film formation or difference with the increase of Zn 2 + concentration; PO4 content greatly affects the phosphating film weight, and improves PO4. The content increases the phosphate membrane weight. 2, the alkaline electropolishing process of aluminum The alkaline polishing solution system was studied, and the influence of corrosion inhibitor and viscosity agent on the polishing effect was compared, the alkaline solution system with good polishing effect was successfully obtained, and the additives that can reduce the operating temperature, prolong the service life of the solution and improve the polishing effect for the first time. The experimental results show that adding appropriate additives to NaOH solution can produce good polishing effect. Exploratory experiments also found that the surface reflectivity of aluminum could reach 90% after using NaOH solution under some conditions, but due to the unstable factors in the experiment, further study is needed. The feasibility of polishing aluminum by DC pulse electropolishing under alkaline conditions is explored. The results show that the pulse electropolishing method can achieve the leveling effect of DC constant voltage electropolishing, but the leveling speed is slow. 3, aluminum and aluminum alloy environmentally friendly chemical polishing Determine the development of a new environmentally friendly chemical polishing technology based on phosphorosulfuric acid, which aims to achieve zero emission of NOx and overcome the quality defects of previous similar technologies. The key to the new technology is to add some compounds with special role to the base liquid to replace nitric acid. To this end, it is necessary to analyze the chemical polishing process of aluminum, especially to focus on the role of nitric acid. The main role of nitric acid in aluminum chemical polishing is to inhibit point corrosion and improve the throwing brightness. Combined with the chemical polishing test in pure phosphoric acid, that the special substances added in phosphoric acid should be able to inhibit the point corrosion, slow down the total corrosion, and must have a better leveling and brightening effect 4. Electrochemical surface reinforcement treatment of aluminum and its alloys The process, properties, morphology, composition and structure of ceramic amorphous composite conversion film formed by anodic oxidation deposition in the process and mechanism of film formation are preliminarily discussed. Process study results show that in the Na _ 2 WO _ 4 neutral mixing system, the control film forming promoter concentration is 2.5~3.0g/l, complexing membrane forming agent concentration is 1.5~3.0g/l, Na _ 2 WO _ 4 concentration is 0.5~0.8g/l, peak current density of 6~12A / dm ~ 2, weak stirring, complete and uniform, good gloss gray series inorganic nonmetallic film layer can be obtained. The thickness of the film layer is 5~10 μ m, and the microhardness is 300 ~ 540 HV, with excellent corrosion resistance. The neutral system has a good adaptability to aluminum alloy, anti-rust aluminum, forging aluminum and other series of aluminum alloy can be better film formation.

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