How long do neodymium magnets last

How long do neodymium magnets last?

Neodymium magnets, or rare earth magnets, are a solid type of magnet commonly used in various applications. From industrial and construction use to arts and crafts, neodymium magnets are everywhere. But one question often arises: how long do neodymium magnets last? This article will answer these critical questions and discuss the factors that affect the longevity of these powerful magnets.

How long do neodymium magnets last
How long do neodymium magnets last?

How long do neodymium magnets last?

These magnets can maintain their magnetism for decades under normal conditions. Indeed, you can expect a high-quality neodymium magnet to work efficiently for 30, 50, or even 100 years.

A study on the measurement of magnetization loss of Nd magnets was carried out at Beijing Sanhuan Research Institute, China, over more than 12 years (4441 days), with an experimental sintered Nd-Fe-B magnet with an endogenous coercivity HcJ=18kOe, a sample of an uncoated cube with a side length of 10.2mm, a permeability coefficient Pc=-2 (click Magnetic Moment, Flux and Remaining Magnetism to learn what is the Pc value), a sample of 8 pieces, directly exposed to the atmospheric environment in which the laboratory is located, at temperatures between 22°C and 28°C, and observations and measurements were performed once a year for 12 years.

Magnetic flux data of Nd-Fe-B magnet samples
Magnetic flux data of NdFeB magnet samples
Magnetic flux loss rate of sintered NdfeB magnet
Magnetic flux loss rate of sintered NdFeB magnet

From the above data, it can be observed that the relative flux loss measured in the first 6 years was essentially insignificant, with an inflection point near 2208 days (about 6 years). Externally, rust spots are visible on the surface of the black sheet magnets after 6 years of placement, which means that oxidation and corrosion have started on the surface and inside of the magnets, and the extent of oxidation or corrosion will continue to expand over time.

The rate of performance degradation is significantly accelerated. In addition, the experiment extrapolates the flux loss from the currently measured 4441 days (12 years and 2 months) to 30-50 years, with less than 1% flux loss expected at 30 years and about 1.3% flux loss at 50 years, with 2% corresponding to about 150 years. (Hollow dots in the figure above)

This result shows that if the lifetime of a magnet is defined as the time corresponding to a flux loss rate equal to 5%, even if the magnet is at a surface not coated for corrosion resistance, the currently measured sintered NdFeB magnets still have a very long lifetime, conservatively estimated at 30-50 years.

Understanding the Lifespan of Neodymium Magnets

The lifespan of neodymium magnets varies depending on the application, usage, and environment. Neodymium magnets can last up to 20 years if properly maintained and used within their specified limits. However, certain factors such as temperature, humidity, magnetic field strength, and mechanical stress can affect their lifespans.

Factors Affecting the Lifespan of Neodymium Magnets

Temperatura

The most crucial factor that impacts the performance of neodymium magnets is temperature. These magnets can lose some of their magnetism when exposed to high temperatures. Each neodymium magnet has a specified maximum operating temperature, which is typically between 80°C and 220°C (176°F and 428°F). Exceeding this limit can cause irreversible damage and reduce the magnet’s lifespan.

Corrosión

Due to their iron content, neodymium magnets are prone to corrosion. Manufacturers usually apply a protective coating, such as nickel, zinc, or epoxy, to prevent this. However, the magnet can corrode if the coating becomes damaged, potentially reducing magnetic performance.

Magnetic Field Strength

Exposure to strong magnetic fields can also affect the lifespan of neodymium magnets. High magnetic fields can cause the magnet to demagnetize or lose its magnetic properties, mainly if it is not designed to withstand such fields. Using neodymium magnets within their specified magnetic field strength limits is vital to ensure their longevity.

Mechanical Stress

Neodymium magnets are brittle and break easily if subjected to excessive mechanical stress or impact. Dropping, hitting, or bending the magnet can cause it to fracture or break, reducing its lifespan. To prevent damage, it is crucial to handle neodymium magnets carefully and avoid subjecting them to excessive stress.

Do neodymium magnets wear out?

Yes, neodymium magnets can be damaged or demagnetized if exposed to excessive heat, strong electromagnetic fields, or physical shock. In such circumstances, the magnetic domains within the magnet may become misaligned, leading to a drop in performance. Additionally, exposure to corrosive environments or strong oxidizing agents can lead to the degradation of the magnet’s surface, which may also impact its magnetic strength over time.

Despite these potential factors, if neodymium magnets are maintained properly and not subjected to significant stress, they will likely maintain their magnetic charge for an incredibly long time. Their lifetime can be expected to last for several decades.

Do neodymium magnets get weaker over time?

Yes, neodymium magnets lose their strength over time, but this process is slow and can take many years or decades. This natural phenomenon is known as magnetic decay and is attributed to various factors such as temperature, magnetic field direction, and time.

How to preserve neodymium magnets for maximum lifespan?

Neodymium magnets are highly resistant to demagnetization and stay magnetic for a long time. However, the service life of neodymium magnets will be affected by various factors such as temperature, humidity, magnetic field, and physical damage. You can keep neodymium magnets for maximum lifespan by following these tips.

Use a magnet keeper

A magnet keeper is a small metal rod with a handle on one end and two opposing poles on the other. When placed between two magnets, it keeps them from clacking together and damaging their surfaces. Additionally, it helps reduce the risk of demagnetization due to prolonged contact with other magnets or magnetic fields.

Store Magnets in Pairs

To prevent the two south or two north magnet poles of different magnets from touching, you should store neodymium magnets together in pairs with the unlike poles. This will help prevent them from repelling each other, which can cause damage and weaken their strength over time. 

Avoid Ferromagnetic Storage Containers

It would be best if you permanently stored them away from other magnets and ferromagnetic materials, as these can cause the magnet to lose its magnetic properties over time. Additionally, it’s important to avoid storing them in ferromagnetic containers such as metal boxes or cans. This is because the container can become magnetized, damaging the magnets inside. 

Store and use neodymium magnets at proper temperatures

Temperature is a crucial factor affecting the life of neodymium magnets. These magnets start to lose their magnetism at temperatures above 80°C. If the temperature exceeds this limit, the magnet will rapidly demagnetize.

Keep Neodymium Magnets in a Dry Environment

If exposed to high humidity, the magnets can corrode and rust, causing the magnetic field to degrade.

Store Away from Electric Currents

Storing them away from electric currents is essential because strong currents can disrupt the magnetic field of a magnet and cause it to demagnetize. This includes direct current sources such as batteries and any electromagnetic field.

Keep them away from strong magnetic fields

Imanes de neodimio can begin to demagnetize if exposed to a strong magnetic field, resulting in a loss of magnetic force. Therefore, keeping neodymium magnets away from strong magnetic fields is essential to ensure their longevity.

Avoid any physical damage

Neodymium magnets are brittle and may crack or break if dropped or subjected to physical shock. Therefore, neodymium magnets must be handled carefully and avoid physical damage to ensure longevity.

How long do rare earth magnets last?

Rare earth magnets are incredibly durable and typically last a long time. Depending on their environment, they can last 30 to 100 years or even longer. If the magnet is exposed to extreme temperatures or is frequently moved around, its lifespan will be reduced.

To ensure your rare earth magnet lasts as long as possible, storing them in a cool, dry place away from any magnetic fields that could interfere with its performance is essential. Additionally, avoid dropping them or exposing them to sudden impacts that could damage the magnet. 

In summary

The lifespan of a neodymium magnet will vary depending on many factors, including temperature, humidity, magnetic fields, and physical damage. Neodymium magnets can last up to 100 years if properly stored and used in the right environment and following the tips in this article. By considering these factors, you can ensure your neodymium magnets will last as long as possible.

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