Ferrite: low and medium, lowest price, good temperature characteristics, corrosion resistance, good performance-price ratio.

NdFeB: the highest performance, medium price, good strength, not resistant to high temperature and corrosion.

Samarium cobalt: high performance, highest price, brittle, excellent temperature characteristics, corrosion resistance.

Alnico: low and medium, medium price, excellent temperature characteristics, corrosion resistance, poor interference resistance.

Samarium cobalt, ferrite, NdFeB can be manufactured by sintering and bonding methods, sintering magnetic properties are high, molding is poor, bonding magnets have good formability, and the performance is much reduced. AlNiCo can be manufactured by casting and sintering methods, casting magnets have higher performance and poor formability, sintered magnets are low, and moldability is better.

Analogy of the performance of different types of magnets?.

How do you define the properties of a magnet?

There are three main performance parameters to determine the performance of the magnet:

Residual magnetic Br: After the permanent magnet is magnetized to technical saturation and the external magnetic field is removed, the retained Br is called the residual magnetic induction strength.

Coercive force Hc: To reduce the B of the permanent magnet magnet magnetized to technical saturation to zero, the reverse magnetic field strength that needs to be added is called magnetic inductive coercivity, referred to as coercive force.

Magnetic energy product B H: represents the magnetic energy density established by the magnet in the air gap space (the space between the two poles of the magnet), that is, the magnetostatic energy per unit volume of the air gap.

How are magnetic materials divided?

Metal magnetic materials are divided into two categories: permanent magnet materials and soft magnetic materials. Generally, materials with an intrinsic coercivity greater than 0.8kA/m are called permanent magnet materials, and materials with an intrinsic coercivity of less than 0.8kA/m are called soft magnetic materials.

The magnetic force of several types of commonly used magnets is compared, and the magnetic force is arranged from largest to smallest: NdFeB magnet, samarium cobalt magnet, Alnico magnet, ferrite magnet.