Dans le domaine des matériaux magnétiques, rare earth permanent magnets and ferrite magnets are the two most widely used types. They not only have significant differences in composition, performance and manufacturing process, but also play an irreplaceable role in their respective application scenarios. Understanding the difference between these two types of magnets will help you make more reasonable decisions when selecting and applying them.
Rare earth permanent magnets: high-performance magnetic materials
Rare earth permanent magnets mainly refer to neodymium iron boron (Ndfeb) and samarium cobalt (SMCO). They are known as the “king of magnets” for their excellent magnetic properties.
Features:
- Extremely high magnetic energy product ((Bh)max)
The magnetic energy product of neodymium iron boron can reach up to 50 MGOe or more, which is about 10 times that of ordinary ferrite, which means that the same volume can output a stronger magnetic field.
- High coercivity
Rare earth permanent magnets are not easily demagnetized by external magnetic fields, and are particularly suitable for occasions that require strong magnetic force and stability, such as motors, générateurs, magnetic resonance equipment, etc..
- Differences in temperature adaptability
NdFeB magnets have poor temperature resistance, and their magnetism drops significantly when the temperature exceeds 150°C; SmCo magnets have better high-temperature stability, and the maximum operating temperature can reach 350°C.
- Easy to oxidize
En particulier, the surface of NdFeB magnets is prone to oxidation and corrosion, so electroplating or coating protection is usually required.
Typical applications:
- High-performance motors (new energy vehicle drive motors)
- Magnetic resonance imaging devices
- Precision instruments
- Magnetic separation devices
Aimants en ferrite: an economical and durable choice
Ferrite magnets are sintered from iron oxide and metal oxides such as strontium and barium, and are the largest type of permanent magnet material.
Features:
- Low cost
Ferrite raw materials are abundant, the process is simple, and the price is low, so it is suitable for large-scale production.
- Moderate magnetic properties
The magnetic energy product is usually 3~5 MGOe, which is much lower than rare earth permanent magnets, but it is sufficient for applications with low to medium magnetic field strengths.
- Excellent corrosion resistance
Ferrites are chemically stable and not easy to rust or oxidize, so no additional protective layer is required.
- High temperature resistance
Ferrites can be used for a long time below 250°C with stable performance.
Typical applications:
- Speakers
- Refrigerator door seal magnetic strips
- Motor rotors
- Magnetic separators
- Teaching and process magnets
The main differences between rare earth permanent magnets and ferrite magnets:
| Comparison Dimension | Rare Earth Permanent Magnets | Ferrite Magnets |
| Maximum Energy Product | High (up to over 50 MGOe) | Medium to Low (around 3-5 MGOe) |
| Cost | High | Low |
| Temperature Resistance | Lower for NdFeB,higher for SmCo | High |
| Corrosion Resistance | Prone to oxidation,requires coating | Chemically stable, not easily corroded |
| Typical Applications |
High-end motors,medical equipment, aérospatial |
Household appliances,magnetic toys, simple separators |
Conclusion:
Both high-performance rare earth permanent magnets and economical and practical ferrite magnets are essential basic materials for modern industry. Only by reasonably understanding their differences and characteristics can we be at ease in design, procurement and application. If you have more questions about specific application areas, please consult Jlmag further. We will provide you with professional product consulting services.
