Application of amorphous and nanocrystalline in inductors

In inductors, we often hear amorphous, nanocrystalline. Today, we will make a detailed introduction to the relevant knowledge. Amorphous alloy is a new type of alloy material that came out in the 1970s, its formation process is the liquid metal, rapid cooling and solidification, and a short-range ordered, long-range disordered ribbon material is obtained.

At present, amorphous (nanocrystalline) materials can be divided into four categories: Fe-based amorphous, Fe- nickel based amorphous, cobalt based amorphous and nanocrystalline.

1. Fe- based amorphous

The main components of Fe-based amorphous are Fe, silicon, boron, carbon, etc., which is characterized by strong magnetism, saturation magnetic induction intensity of up to 1.4~1.7T, cheap, most suitable for replacing silicon steel sheet use, suitable for frequency 10kHz below the application scenario.

2. Fe-nickel-based amorphous Fe-Nickel-based amorphous is mainly composed of iron, nickel, silicon, boron, etc. Its saturated magnetic induction strength is about 1T and its permeability is high, which can be used to replace silicon steel sheet and permalloy, often used in transformer related products.

3. Cobalt-based amorphous

The main components of cobalt-based amorphous are cobalt, silicon, boron, and sometimes other elements are added in order to meet the needs of certain properties. Its saturation magnetic induction intensity is about 1T, its permeability is high, and it is generally used in products with relatively high requirements and can be used instead of ferrite. However, due to the rare metal cobalt, the price is very expensive.

4. Nanocrystalline

Nanocrystalline are composed of Fe , silicon, boron and a small amount of copper and niobium, of which copper and niobium are important raw materials for obtaining nanocrystalline. They are first processed into amorphous strips, and then heat treated to obtain a mixture of nanocrystalline and amorphous materials. Nanocrystals have superior performance and relatively cheap price, and are widely used in various high-frequency transformers and inductors

From the application point of view, the frequency range of amorphous (nanocrystalline) materials is 50Hz to 100kHz. It has good magnetic properties: high magnetic induction intensity, high initial permeability, high resistivity, high residual magnetic induction intensity, low coercivity, low high-frequency loss, is a very excellent comprehensive performance of magnetic materials. The main advantages of the application of amorphous (nanocrystalline) in transformers and common mode inductors are as follows:

1. The effective permeability is high, the coil number is small and the volume is small under the same inductance.

2. Few turns, small distributed capacitance;

3. Low coercivity, low loss;

4. Curie high temperature, good stability;

5. Good frequency characteristics, good effect on dealing with noise spikes. Amorphous (nanocrystalline) greatly improves the efficiency of transformers and inductors, reduces the volume, reduces the weight, and reduces the energy consumption, so it is currently widely used in high-power switching power supplies, inverter power supplies, UPS power supplies, charging piles, automotive electronics, power monitoring and other fields.