Are neodymium magnets permanent?

Are neodymium magnets permanent?

Neodymium magnets are becoming increasingly popular due to their high-grade strength and ability to remain magnetized for extended periods. This article will discuss whether neodymium magnets are permanent, outlining their properties and features which enable them to retain their magnetic charge. Neodymium magnets can make a great addition to any project as they come in various shapes and sizes, making it easy to find the perfect magnet for your needs.

Are neodymium magnets permanent?
Are neodymium magnets permanent?

Are neodymium magnets permanent?

Yes, neodymium magnets are strong permanent magnets primarily made of an alloy of rare earth metal neodymium, metal iron, and boron (NdFeB). Unlike temporary magnets like iron magnets, neodymium magnets do not lose their magnetism over time. However, it is essential to note that neodymium magnets can demagnetize under certain conditions, such as exposure to high temperatures or strong electromagnetic fields.

Qu'est-ce qu'un aimant néodyme ?

NdFeB is a rare earth permanent magnet compound composed of rare earth metal neodymium, metal element iron, non-metal element boron and a small amount of added elements such as praseodymium, dysprosium, niobium, aluminum, gallium, copper and other elements. Simply speaking, it is a kind of magnet known as magnetic steel. NdFeB permanent magnet has excellent magnetic properties, lightweight and low price, and has a wide range of applications. It is known as the “magnet king” and is the most cost-effective magnet material.

The magnetic field of a magnet

If you hold a magnet close to a nail, you will find that the magnet attracts the nail even though it is not in contact with it. The magnet can attract the nail without touching it. This is because the magnet can generate a magnetic field, and the force generated by the magnetic field “pulls” the nail over. Any magnet has two magnetic poles: the N and S poles. Magnetic fields have the property of like-polarity repulsion and opposite-polarity attraction.

Factors that affect the magnetism of neodymium magnets

The temperature

When the temperature of the magnet and the magnet increases, the molecular motion of the magnet becomes more intense, and the disorderly collision between the molecules becomes more violent, which breaks the orderly balance of the molecules, and the magnetism will weaken a lot.

When the temperature rises to a specific value, the violent molecular thermal motion finally destroys the regularity of the electron motion direction, and the magnetism of the magnet disappears. Metallographers refer to the temperature at which the magnet completely loses its magnetism as the “Curie temperature.” The Curie temperature of NdFeB is 320°C-460°C

The electromagnetic fields

Suppose we put the magnet into a space that can generate an AC magnetic field. In that case, the internal structure of the magnet will be disrupted after being disturbed by the AC magnetic field so that demagnetization can be achieved. This method is a relatively common demagnetization method.

How can neodymium magnets be demagnetized?

High-temperature demagnetization method

The main operation of the high-temperature demagnetization method is to heat the magnet into a high-temperature furnace with a hot air gun. After high-temperature treatment, the magnetism of the strong magnet will be removed, but the high temperature will directly cause. The object’s structure inside the magnet changes drastically, so this demagnetization method is generally used for scrapped and recycled magnets.

Vibration demagnetization method

The operation of this method is effortless. It is to vibrate the powerful magnet strongly and violently. After the vibration process, the magnet’s internal structure changes, thereby changing the physical properties of the magnet. Generally speaking, the effect of this demagnetization method is adopted. Not big, only a tiny amount of demagnetization can be used temporarily.

AC demagnetizer

This demagnetization method puts the magnet into a space that can generate an AC magnetic field. After the AC magnetic field is disturbed, the internal structure of the magnet will be disrupted so that the effect of demagnetization can be achieved. This method is relatively standard—the method of demagnetization.

The above three methods are adequate for demagnetizing solid magnets, but we prefer the AC demagnetization method. It has a better demagnetization effect than the high-temperature and vibration demagnetization methods, and the efficiency is also high. It is used most in current industrial production.

How to care for and handle neodymium magnets?

To keep neodymium magnets in good condition, you should store them away from other magnets or magnetic fields. If you need to handle a magnet, wear gloves or another barrier between your skin and the magnet. This will prevent pinching and other injuries. Also, don’t let neodymium magnets bump into each other, as they can crack or chip easily. Finally, if you’re using them outdoors, give them a protective coat of paint or epoxy to prevent corrosion and weather damage.

In conclusion

Neodymium magnets are permanent magnetic materials due to their solid internal structure. They offer high remanence, coercivity, and energy products for various applications. While it may be possible to slightly reduce the magnetism of these magnets with exposure to heat or electromagnetic fields, they remain one of the most reliable and cost-effective options for many industries. Therefore, anyone looking for a powerful, long-lasting magnetic solution should consider utilizing aimants en néodyme in their project.

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