The excellent characteristics of amorphous nanocrystalline soft magnetic materials make it suitable for high-power medium and high frequency transformers, high-frequency switching power supplies, electromagnetic compatibility devices, high-precision current transformers, high-frequency current samplers, and magnetic sensors in various electronic instruments and equipment. and other devices. However, there are also problems in practical application promotion. For example, in the process of applying to inverter power supply, there have been some problems such as noise, brittleness, consistency, etc., we would like to  briefly describe the reasons for these problems here.

What are some of the issues that people are concerned about

I. Noise problem

1. The reason for the magnetostriction coefficient of the material itself is that the magnetostriction coefficient of the ferrite material is relatively large, although the ferrite core is solid, it will sometimes appear noise in use. Nanocrystalline composition is different, different magnetostriction coefficient, using a few years ago, is a kind of common alloy composition, thus make the noise problem of transformer is more outstanding, with the application and development is more and more, for different purposes by different alloy component, to meet the special requirements of different components on the magnetic. For example, as power output transformers, current transformers, common mode inductors, etc., have been developed special components. According to the requirements of the power transformer to adjust the alloy composition, reduce the magnetostriction coefficient, the user proved that the noise problem has been greatly improved

2. The reason for the core winding tightness, which has a great relationship with the quality of the used strip, strip size deviation, uneven thickness will cause the core winding is not tight, easy to produce noise.After adjusting the composition, the liquid steel has good fluidity, which is beneficial to the forming quality of the strip, and provides a favorable guarantee to reduce the noise of the iron core to a certain extent.

3. The problem of inverter circuit, the DC component in the circuit is large, resulting in the working magnetic induction of the iron core, causing noise.Our experiments show that the noise increases with the increase of working magnetic induction.Some manufacturers have adopted DC isolation measures on the circuit, and the use of nanocrystalline iron cores has not produced noise problems for many years.

II. Brittleness problem

The brittleness of nanocrystalline core is mainly reflected in the slag removal of the core, which is the biggest problem reported by users. It is not only a headache for the installation and operation, but also easy to cause the hidden danger of short circuit. After years of practice and research, the brittleness problem has been greatly improved by adjusting the composition and process. After composition adjustment, the flexibility of the strip was significantly improved. The thinning of strip thickness also reduces brittleness. In addition, in the process of manufacturing the iron core, the iron core is soaked with stress-free glue, so that the iron core is not easy to break, and the brittleness of the iron core slag is completely solved. At the same time, the non-stress adhesive fixed the layer gap of the core strip, so that it is not easy to produce resonance, and the noise is reduced.

III. consistency issues.

Consistency is related to the scale of production and the capacity of production equipment. From the quality of the strip, a 500 kg output equipment and 50 kg output equipment, the same production of 500 kg strip, obviously, the former product in the composition, magnetic consistency is better than the latter. The same goes for heat treatment in the production process. Therefore, large production scale and large capacity of production equipment are beneficial to consistency.

The consistency of nanocrystalline is mainly manifested in the large dispersion of saturation voltage and inductance, sometimes the difference is more than double. The main reasons are the poor effect of magnetic heat treatment and the lack of classification and screening in production inspection. With the adjustment of the composition of the power transformer, it not only improves the brittleness, but also reduces the residual magnetic induction intensity of the material. Therefore, it increases the effect of magnetic heat treatment, improves the saturation voltage of the iron core, and plays an important role in product consistency.

The magnetic properties required by the inverter power supply, there is a gradual understanding of the process, a few years ago, because the amount of small, only emphasize the loss to meet the requirements of it. Therefore, the performance test only measures the loss parameter. For specific users, increase the test induced voltage value. With the increasing number of applications, various requirements are put forward, especially the requirement of performance consistency. Because there is a process of recognition of this requirement, there is some lag in terms of composition improvement, production organization, testing standards, etc. Therefore, it has a certain impact on the promotion and application. Now that the problem has been sufficiently recognized and a variety of effective measures have been taken, the consistency has been greatly improved.

IV. issue of price

Price is of primary concern to users, especially those who are ready to use or just starting to use. Price and output has a direct relationship, in recent years, with more and more widely in the application of nanocrystalline iron core fields, not only used in inverter welding machine, and a large number of used in electrolytic plating equipment, induction heating equipment, charging equipment, communication power supply, UPS power supply, X optical source, laser power, frequency control of motor speed, power and other fields, production is more and more big, the price also have a greatly reduced, The current price has been reduced by about 40% from the original price, and as the amount of application continues to increase, the price will be lower and lower, and the price of nanocrystalline will be closer and closer to the price of ferrite.

At present, the price of nanocrystalline iron core is lower than that of ferrite iron core for power supply of more than 15 kW, Because the size of ferrite core is limited, it is difficult to solve the core needed by high-power transformer, and several cores have to be used to meet the power requirements. A nanocrystalline core will do. From the unit price, ferrite is much cheaper, but the total price of several iron cores is higher than the price of nanocrystalline iron cores.

In the process of applying nanocrystalline magnetic ring core (ultramicrystalline iron core) to inverter power supply, these problems such as noise, brittleness, consistency and price, etc. have influenced the popularization and application to a certain extent, and attracted attention. But now these problems have been gradually solved, and we look forward to discussing the advantages and disadvantages of amorphous nanocrystalline materials with you.