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The Reason Of Material Migration In NdFeB Segment
Nov 02, 2017

The reason of material migration in NdFeB Segment
NdFeB Segment At the final stage of sintering, there is usually a volume migration of matter that includes plastic flow, grain boundary diffusion, viscous flow, volume diffusion, and the migration of substances on the surface of the particles that cause sintering.
The above changes depend on the sintering stage, the temperature, the particle size of the powder and the material composition, although the above process is not easily observed, but it is present. This phenomenon was observed when the NdFeB Segment film was dynamically observed by JEM-lOOOkV ultrahigh voltage electron microscope.
The surface migration and volume migration of the material is the sintering process, there are two types of material migration mechanism. The migration of substances caused by the flow of matter on the surface of the particles is called surface migration of sintered substances such as surface expansion and evaporation - agglomeration.
Surface diffusion and evaporation - agglomeration in the control of sintered matter surface migration are two more important components of the Zai part. Volume diffusion from the surface source to the surface well is possible. The volume migration of the material during sintering can cause a change in the basic size of the sintering body. Most of the bulk movement of the material in the final phase of the sintering process. Volume diffusion, grain boundary diffusion, viscous flow, and plastic flow are all within the range of volume migration mechanisms of matter. The importance of the sintering mechanism is seen from the material, the powdery degree, the sintering stage, the sintering temperature, and some other process parameters.
NdFeB Segment is very susceptible to corrosion. Therefore, most of the finished products to be plated or painted. Conventional surface treatment includes: nickel (nickel-copper-nickel), galvanized, aluminum, electrophoresis and so on. If you work in a confined environment, you can also use the way of phosphating.
NdFeB Segment is currently widely used, the rapid development of magnet products. NdFeB Segment from the invention to the present wide application, but also more than 20 years time. Because of its high magnetic properties and ease of processing, the price is not very high, so the application area to expand rapidly. At present, the commercialized NdFeB Segment, magnetic energy product can reach 50MGOe, is ferrite 10 times.
NdFeB Segment is also a powder metallurgy product, processing and samarium cobalt similar. At present, NdFeB Segment maximum operating temperature of 180 degrees Celsius. If it is harsh environment applications, generally recommended no more than 140 degrees Celsius.
NdFeB Segment Features: NdFeB Segment has very excellent magnetic properties compared with permanent magnet materials such as ferrite, and its magnetic energy is much higher than other magnets, and can be called "one generation magnetic king". NdFeB Segment is widely used in packaging, toys, gift crafts, fitness magnetron, motor, micro Motors, computers, instruments, meters, motorcycles, cameras, watches, audio, home appliances, office automation, magnetic therapy and daily life in all areas.
Due to the high magnetic properties of the NdFeB Segment, it is used in many cases to replace other magnetic materials to reduce the product volume. If the use of ferrite magnets, now the size of the phone, I am afraid it will be less than half of the bricks.
The actual application of NdFeB Segment permanent magnet shape is a variety of, such as discs, cylinders, cylindrical (with holes); square, square, square column; tile, fan, trapezoidal, polygonal and various Rule shape and so on. Each shape of the permanent magnets have different sizes, the production process is difficult to achieve a molding. The general production process is: Mr. production of large (large size) of the blank, after sintering and tempering treatment, and then through the mechanical processing (including cutting, drilling) and grinding processing, surface coating (coating), and then Magnet performance, surface quality and dimensional accuracy of the test, and then magnetizing, packaging and factory.

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