Magnetic materials are one of the primary raw materials for electric motors and significantly impact motor performance.

Magnetic materials are one of the primary raw materials for electric motors and significantly impact motor performance.

(1) Motors typically utilize materials with strong magnetic properties. Strong magnetic materials encompass permanent magnet materials, soft magnetic materials, and functional magnetic materials.

Permanent magnets retain their magnetization after initial magnetization, whereas soft magnetic materials magnetize easily but demagnetize readily. Permanent magnets are currently classified into three major categories: metallic permanent magnets, ferrite permanent magnets, and rare-earth permanent magnets. Soft magnetic materials include ferrite soft magnetic materials, metal powder cores, metallic soft magnetic materials, and amorphous/nanocrystalline materials. The most significant difference between these two types of magnetic materials lies in their coercivity. Coercivity is defined as the strength of an external magnetic field required to reverse the magnetization of a magnetized material, preventing it from releasing energy to the external magnetic circuit (though the magnet retains internal energy). It is measured in Oe or A/m.

(2) Higher coercivity makes the material more resistant to demagnetization

1) Permanent magnet materials aim to continuously pursue higher coercivity to enhance demagnetization resistance, finding extensive application in permanent magnet motors;

2) Soft magnetic materials achieve electrical parameter conversion by reducing coercivity and pursuing higher permeability, thereby enhancing magnetic component efficiency and saving space. They are currently used as cores in various motors, transformers, relays, inductors, filters, and other components across new energy vehicles, robotics, photovoltaics, and numerous other fields.

(3) Neodymium-iron-boron exhibits superior performance with potential for permeability enhancement

Neodymium-iron-boron materials demonstrate outstanding coercivity and superior magnetic energy product compared to other materials. A higher magnetic energy product means smaller neodymium-iron-boron volume per unit magnetic field strength, significantly contributing to motor space savings. High-performance NIBO magnets (with a combined coercivity and energy product exceeding 60) can significantly reduce motor size, lower motor weight, minimize energy losses, and enhance overall motor system efficiency. The sole drawback is relatively poor temperature stability, which requires adding elements like cobalt to improve thermal performance, resulting in higher costs.

(4) Domestic Drive Motor Raw Materials Hold Significant Advantages

Regarding raw materials, neodymium-iron-boron permanent magnets represent a resource advantage for China, while silicon steel can largely be substituted with domestic products. As a traditional manufacturing sector, China boasts numerous stator and rotor producers. Overall, domestic drive motor raw materials possess distinct advantages.