What Are The 4 Kinds Of Permanent Magnets?

In the field of modern industry and technology, permanent magnets are key basic materials and are widely used in new energy, electronic equipment, aerospace and other industries. Alnico, ferrite, samarium cobalt and neodymium iron boron, four types of permanent magnets, play an important role in different scenarios with their unique performance advantages.

Table of contents

●AlNiCo permanent magnet: a strong defender of high temperature environment
●Ferrite permanent magnet: an economical and practical popular material
●SmCo permanent magnet: a combination of high performance and high stability
●NdFeB permanent magnet: the "king of magnets" leading modern industry
●Performance comparison of four types of permanent magnets
●Industry development trends and prospects

Al-Ni-Co permanent magnet: A defender of high temperature environment

Al-Ni-Co permanent magnet is one of the earliest developed Permanent Ferrite Magnet materials, mainly composed of aluminum, nickel, cobalt and iron. Its biggest feature is that it has excellent temperature stability, low reversible temperature coefficient, and can work stably in high temperature environment above 600℃. It is the preferred material in aerospace, high temperature sensor and other fields. In aircraft engines and missile guidance systems, Al-Ni-Co permanent magnets provide stable magnetic fields for key components to ensure the precise operation of equipment in extreme environments. In addition, its good machining performance enables it to be made into complex shapes to meet diverse needs. However, its low magnetic energy product limits its application in scenes with extremely high requirements for magnetic field strength. ​

Ferrite permanent magnet: an economical and practical popular material

Ferrite permanent magnet is mainly composed of iron oxide, with elements such as barium and strontium added. It has become the most widely used permanent magnet because of its abundant raw materials and low price. It has high coercivity, strong anti-demagnetization ability, good corrosion resistance and insulation, and does not require complex protection. In daily life, ferrite permanent magnets are widely used in refrigerator door seals, electric shaver motors, and speakers and headphones in electronic devices. Electric meters, water meters, and small motors in the industrial field also rely on their stable performance. However, the low magnetic energy product makes it difficult to meet the high-end strong magnetic field requirements, and it is mainly used in the mid- and low-end markets.

Samarium cobalt permanent magnet: a combination of high performance and high stability
Samarium cobalt permanent magnet is a rare earth permanent magnet material composed of elements such as samarium and cobalt. Its magnetic energy product can reach 14-28MGOe, with high coercivity, a maximum operating temperature of more than 350℃, and minimal magnetic property decay at high temperatures. In the field of aerospace, satellite attitude control systems, aircraft high-temperature sensors; missile guidance systems and submarine propulsion motors for national defense and military industries; as well as industrial high-end equipment and medical equipment, are all inseparable from the stable and strong magnetic field provided by samarium cobalt permanent magnets. However, due to the high cost of raw materials containing rare earth elements, its large-scale application is limited, and it is mainly concentrated in high-end fields with demanding performance requirements. ​

Neodymium iron boron permanent magnet: "Magnetic King" Leading Modern Industry
As the third-generation rare earth permanent magnet material, neodymium iron boron permanent magnet is called the "magnetic king" with a magnetic energy product of more than 50MGOe. It can generate a strong magnetic field in a small volume, helping to miniaturize and lighten equipment. In the field of new energy vehicles, it is the core material of the drive motor, improving the energy efficiency of the vehicle; in wind power generation, the NdFeB Ferrite Arc Magnets direct drive generator improves the power generation efficiency; the speakers and vibration motors of electronic devices such as mobile phones and computers also rely on it to achieve high performance. However, its Curie temperature is low (generally 310-370℃), and it is easy to oxidize and corrode, so it needs surface coating treatment.

Performance comparison of four major permanent magnet types

Industry Development Trends and Outlook ​
With the rapid development of emerging industries such as new energy and intelligent manufacturing, the requirements for permanent magnet performance are constantly increasing. In the future, the research and development of Permanent Ferrite Magne tmaterials will focus on improving performance and reducing costs. On the one hand, optimize the existing material process, such as improving the high temperature resistance and corrosion resistance of NdFeB permanent magnets and reducing the cost of SmCo permanent magnets; on the other hand, actively explore new permanent magnet materials. At the application level, permanent magnets will continue to expand their market share in new energy vehicles, wind power generation and other fields, while opening up new application scenarios in cutting-edge fields such as medical care and quantum computing, and promoting the upgrading and development of related industries.