英语
日语
德语The main components of NdFeB magnets include iron and neodymium, of which neodymium has extremely high electrochemical activity, and iron is relatively rich. These two elements are very easy to react chemically in a specific environment, which in turn causes corrosion. Corrosion not only causes damage to the appearance of the magnet, but more seriously, it may cause its magnetic properties to fail completely, directly affecting the performance and service life of the magnet. In order to ensure that NdFeB magnets can function stably under various working conditions, it is particularly necessary to perform effective surface protection treatment on them.
Key causes of NdFeB magnet corrosion
The corrosion of NdFeB magnets is the result of the combined action of multiple factors. From its own composition, the high electrochemical activity of neodymium makes it easy to undergo oxidation reactions when it comes into contact with water, oxygen, etc. As an important component of magnets, iron is easy to form electrochemical corrosion cells in a humid environment, accelerating the corrosion process. When magnets are exposed to an environment containing moisture, salt or other corrosive media, these media will penetrate into the surface of the magnet, react with neodymium and iron, and gradually destroy the structure of the magnet. External conditions such as temperature, humidity, and acidity and alkalinity in the environment will also have a significant impact on the corrosion rate. In an environment with high humidity, large temperature fluctuations, or the presence of corrosive gases, the corrosion rate of the magnet will be significantly accelerated, thereby shortening its effective service life.
Mainstream NdFeB magne surface protection coating
In the field of NdFeB magne surface protection, there are a variety of coating technologies, among which the nickel-copper-nickel (Ni-Cu-Ni) three-layer coating is the most widely used standard coating. This coating can provide a reliable protective barrier for the magnet through the synergistic effect of the three-layer structure, effectively blocking the invasion of external corrosive media. Due to its stable protective performance and strong adaptability, most NdFeB magnets will use this coating for surface protection unless there are special requirements for use. Zinc (Zn) coating has been widely used in some scenarios with relatively low protection requirements due to its low cost advantage. Zinc coating has obvious limitations. In extreme acid and alkaline environments, zinc coating is easily corroded, thereby losing its protective effect on the magnet.
Influence on the protective effect of the surface coating of NdFeB magnets
The protection level of the surface coating of NdFeB magnets is not fixed, but is affected by many factors. In a dry and clean environment, the protective effect of the coating can often be well maintained; in a humid, dusty, corrosive gas or extreme temperature, acid and alkali environment, the protective ability of the coating will be tested to varying degrees, and its service life may be shortened accordingly. The maintenance method of the coating also plays an important role in the protective effect. Even if the coating has excellent performance, if it is not maintained during use, its protective performance will be affected.
Issues to note when using the surface coating of NdFeB magnets
During the use of NdFeB magnets, special attention should be paid to the protection of the surface coating. It should be clear that any coating is not absolutely reliable. Once the coating is scratched or damaged, its moisture-proof protection function will be lost, and external moisture, corrosive media, etc. will directly contact the surface of the magnet, causing corrosion. In daily use, try to avoid physical damage to the surface coating of the magnet. It is necessary to select a suitable coating according to the specific environment in which the magnet is located, and formulate corresponding maintenance measures. During use, the coating should also be checked regularly to promptly detect and deal with possible minor damage to the coating, and to extend the effective protection time of the coating as much as possible, so as to ensure the normal operation of the NdFeB magnet.
Scientifically select the coating for NdFeB magne surface protection
When selecting the coating for NdFeB magne surface protection, it is necessary to consider a variety of factors to ensure that the selected coating can meet the actual use requirements. First of all, it is necessary to clarify the use environment of the magnet, including the humidity, temperature, acidity and alkalinity of the environment, and whether there are corrosive media. If the magnet will be used in an extreme acid and alkaline environment, then the zinc coating is obviously not a suitable choice, and the nickel-copper-nickel three-layer coating may be more suitable. Consider the cost factor. On the premise of meeting the basic protection requirements, for some scenarios with low requirements for protection performance, a lower-cost coating can be appropriately selected to reduce the overall cost. However, it should be noted that the necessary protection performance cannot be sacrificed for the sake of simply pursuing low cost, otherwise it may cause greater losses due to magnet corrosion. It is also necessary to consider the construction process of the coating and the difficulty of subsequent maintenance. Different coatings may require different construction conditions and techniques, and the difficulty of maintenance methods will also affect the maintenance cost and effect in actual use.
