Amorphous core with protection shell

Amorphous (nanocrystalline) materials are all strip materials, so they are very brittle. If they are not wrapped or processed, their force bearing capacity is very poor. To avoid this problem, there are usually two methods: one is surface spraying; the other is to add a protective shell.   Spraying forms a good protective film on the surface of the strip amorphous (nanocrystalline) material, which increases the surface strength and greatly increases its force bearing capacity, so that it can withstand a certain external force. However, spraying only improves the strength of the surface of the amorphous material, and does not change the performance of the matrix, so the magnitude of the force is often limited.   The amorphous sprayed magnetic ring exploded directly during the ring pulling process, which is caused by excessive external force. According to experience, the sprayed magnetic ring can withstand the tension below 0.5mm wire diameter enameled wire, and the good quality can withstand the tension below 0.8mm wire diameter enameled wire. If the wire diameter of the enameled wire exceeds 0.8mm, it is recommended to use a protective shell.   The second is the protective shell solution. In this case, since the magnetic ring is added with a layer of protective shell, the wire diameter is almost unlimited. The main disadvantage is that the shell has a certain thickness, which will increase the volume of the product to a certain extent and reduce the utilization rate of the inner hole of the magnetic ring. However, in terms of reliability, adding a shell is more secure than spraying.   Secondly, amorphous (nanocrystalline) is prone to noise during application. The matrix of amorphous (nanocrystalline) is a strip, and there are certain gaps between the thin sheets. In addition, the differences in the various metal components of amorphous (nanocrystalline) can easily produce magnetostrictive effects, and noise problems will follow.   This puts higher requirements on the quality of the strip. If the strip size deviation is large and the thickness uniformity is poor, resulting in loose winding of the iron core, it will further aggravate the generation of noise.   Third, the production process of amorphous (nanocrystalline) is immature and has poor consistency. Compared with ferrite, the development time of amorphous (nanocrystalline) materials is short, the production process is not very mature, and the scale and automation effects have not been fully reflected. In the application of transformers and inductors, the discreteness of inductance is relatively poor.   Fourth, the price is expensive. Among amorphous and nanocrystalline materials, nanocrystalline is the cheapest. But compared with ferrite, the price is still relatively high. This is related to the raw materials of nanocrystals. The price of the added niobium component is still relatively expensive. Secondly, compared with ferrite, the output of amorphous (nanocrystalline) is limited, and the production process is complicated, which also pushes up the price of amorphous (nanocrystalline) products to some extent.   However, in practical applications, we need to consider the cost comprehensively. The use of amorphous (nanocrystalline) materials will increase the cost of the magnetic core, but greatly reduce the number of winding turns, reduce labor costs, reduce the cost of enameled wires, reduce copper loss and heat generation, and reduce the cost of heat dissipation. Only through comprehensive comparison can we judge whether the amorphous (nanocrystalline) solution is beneficial.