Special cooler for anodizing  

1. Background and development history

The research of micro arc oxidation technology originated from the military needs. In the 1950s, some American arms factories explored this technology; In the middle of 1970s, the former Soviet Union began to study micro arc oxidation technology, and reached a high level of research; In the middle and late 1980s, due to the more extensive use of aluminum based materials and the further improvement of their surface properties, micro arc oxidation technology has become one of the international research hotspots. The United States, Germany, Japan and other industrial developed countries have invested a lot of manpower, material and financial resources in research and development, and have made a lot of research and application achievements in the mechanism, process parameters and technology and industrial application of micro arc oxidation. Micro arc oxidation technology has been widely used in automobile, machinery, electronics, aerospace and other industrial fields, and achieved good economic and social benefits. The research work in this field in China has just started, and great progress has been made in recent years.

2. Advantages and disadvantages and application scope

Micro arc oxidation technology is used to strengthen the surface of aluminum and its alloy materials. It has the advantages of simple process, small floor area, strong treatment capacity, high production efficiency, and is suitable for ten industrial cattle products. Micro arc oxidation electrolyte does not contain toxic substances and heavy metal elements, and has strong anti pollution ability and high recycling rate. Therefore, it has less environmental pollution, meets the needs of high-quality clean production, and meets the needs of China's sustainable development strategy. The ceramic coating on aluminum substrate after micro arc oxidation has high hardness (HV ＞ 1200), strong corrosion resistance (CASS salt spray test ＞ 480h), good insulation (film resistance ＞ 100m Ω), strong adhesion with base metal, good wear resistance and heat shock resistance. The micro arc oxidation technology has strong processing ability, and the oxidation film with different characteristics can be obtained by changing the process parameters to meet the needs of different purposes; It can also change or adjust the composition of electrolyte to make the film have some characteristics or show different colors; In addition, different electrolytes can be used to treat the same workpiece for many times to obtain multilayer ceramic oxide films with different properties.

Because of the above advantages and characteristics, micro arc oxidation technology has a very wide application prospect in machinery, automobile, anti-corrosion, electronics, aerospace, civil construction and other fields. It can be mainly used for surface strengthening of aluminum based parts with special requirements for wear resistance, corrosion resistance, heat shock resistance and high insulation; At the same time, it can also be used in the surface treatment of aluminum substrate with high requirements for decoration, wear resistance and corrosion resistance in construction and civil industry; It can also be used for surface strengthening of special aluminum base alloy materials which cannot be treated by conventional anodizing. For example, aluminum base piston, piston seat, cylinder and other aluminum base parts of automobile and other vehicles; All kinds of aluminum based molds in machinery and chemical industry, inner walls of aluminum cans, and all kinds of aluminum based parts in aircraft manufacturing, such as warehouse floor, rolling bar, guide rail, etc; And various aluminum based hardware products in civil industry, fitness equipment, etc.

There are still some shortcomings in micro arc oxidation technology, such as the research of process parameters and supporting equipment need to be further improved; The oxidation voltage is much higher than that of conventional aluminum anodizing, so safety protection measures should be taken during operation; And the electrolyte temperature rises rapidly, so refrigeration and heat exchange equipment with large capacity are needed.

3. Development prospects

Micro arc oxidation technology is an advanced comprehensive strengthening treatment technology for aluminum and its alloy materials, and its research and development are still in-depth. On the one hand, in basic research, various modern research methods and means are being used to further explore the mechanism of micro arc oxidation. Lay a foundation for industrial application and development. On the other hand, the improvement of micro arc oxidation power supply and supporting equipment, as well as the control and adjustment of process parameters, especially the composition of oxidation electrolyte are being studied more widely and carefully, so as to further meet the needs of various functional film properties and further expand the application field and scope of this technology. For example, the composite micro arc oxidation method can be used to add some insoluble powder materials to the oxidation electrolyte, so that they can be deposited in the oxide film layer in the process of micro arc oxidation to increase the special functions of the film (such as self-lubricating film, high wear-resistant film, etc.). It can be predicted that with the deepening of the basic and Application Research of micro arc oxidation, the technology will be widely used not only in aluminum and aluminum alloy materials, but also in the surface strengthening treatment of other metals such as magnesium, titanium and other metal materials, which will bring good social and economic benefits for the development of China's industry and national economy.

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