According to the difficulty of demagnetization after magnetization, magnetic materials can be divided into soft magnetic materials and hard magnetic materials. The difference between soft magnetic material and hard magnetic material is that the material that is easy to remove magnetism after magnetization is called soft magnetic material. Of course, this material is also extremely easy to demagnetize. Materials that are not easy to demagnetize are called hard magnetic materials. Generally, the remanence of soft magnets is small, and that of hard magnets is large.
Soft magnetic material mainly includes soft magnetic cores and silicon steel sheets. Hard magnetic material mainly includes materials such as nickel cobalt, samarium cobalt, neodymium iron boron, iron oxide and so on. The applications of soft and hard magnetic material are wide. Soft magnetic material is widely used as a path for magnetic lines of force, that is, as a magnetic material. For example, core of transformer and sensor, magnetic shield, switching power supply, display, filter, yoke of special magnetic circuit and so on. Hard magnetic material is mainly used in the fields of motors, electrical appliances, electronics, medical equipment, aerospace, and smart home.
1. They are called differently. Hard magnetic material is generally called permanent magnet, and soft magnetic material is called magnetic core.
2. Their remanence is different. Hard magnetic material has remanence, but soft magnetic material has very little remanence.
3. Their uses are different. After the soft magnetic material is powered off, the magnetism will disappear immediately. After the hard magnetic material is powered off, a part of the magnetism remains. The iron core becomes a magnetic field, and it may be a magnetic field that changes direction continuously. In this way, the transformer becomes a generator, and this extra electricity will cause damage to other electrical appliances. So, this is why power transformers use soft magnetic material instead of hard magnetic material.