The Difference Between Soft Magnetic Materials And Hard Magnetic Materials

Permanent magnetic functional materials are often referred to as permanent magnetic materials, also known as hard magnetic materials, while soft magnetic functional materials are often referred to as soft magnetic materials. Magnetic hardness refers to the ability of magnetic materials to retain their strong magnetism (referred to as magnetism) for a long time after being magnetized by an external magnetic field, characterized by high coercive force (coercive magnetic field). Soft magnetic materials, on the other hand, are magnetic materials that are easily magnetized and demagnetized by applying a magnetic field, meaning they have low coercivity.

Classification of Soft Magnetic Materials

1. Soft magnetic metal materials

Commonly used soft magnetic metal materials include pure iron, low-carbon steel, iron silicon alloy (silicon steel sheet), iron nickel alloy, iron diamond alloy, iron aluminum alloy, etc. For example, the iron silicon alloy, also known as silicon steel sheet, which is widely used in power equipment such as transformers, motors, and generators, is the most commonly used soft magnetic metal material. In industrial production, silicon steel containing about 3.2% Si is often selected, which is annealed and cold-rolled to form very thin plates and strips. Different shapes of iron cores are stacked according to needs, and these materials are also used in engraving machines!

2. Ferrite soft magnetic material

The so-called ferrite is a composite oxide of one or several metal elements with iron as the main component. Ferrite magnetic materials exhibit minimal skin effect and eddy current loss in alternating electromagnetic fields due to their high resistivity. So ferrite magnetic materials are widely used in fields such as radio, high-frequency, microwave, pulse, etc.

3. Amorphous magnetic alloys

Usually, alloy magnetic materials have a crystalline structure, but amorphous metal alloys can be obtained by methods such as vapor deposition, liquid phase rapid cooling, or high-energy ion implantation. In amorphous alloys, the arrangement of atoms is irregular, hence it is also known as metallic glass. It has a series of excellent properties, especially its high resistivity, low eddy current loss, and low resistance temperature coefficient. It has great advantages as a transformer core, magnetic recording, magnetic sensor, and motor material.

The Use of Soft Magnetic Materials

Hard magnetic materials have high residual magnetism and are suitable for use as permanent magnets; Soft magnetic materials have high magnetic permeability and are suitable for use as electromagnets, transformers, etc.

Soft magnetic materials: high magnetic permeability, easy magnetization, easy demagnetization (high initial magnetization). The saturation magnetic induction intensity is high, the coercivity (Hc) is small, the area of the hysteresis loop is narrow and long, and the loss is small (HdB area is small). Including magnetic pure iron, silicon steel permalloy (Fe, Ni) ferrite, etc. Suitable for magnetic cores and bars of relays, motors, and various high-frequency electromagnetic components.