If properly handled, permanent magnets may lose 1% of their magnetic strength in 100 years or more. Do magnets wear out over time? This question tickles many people's minds, as they believe that magnets have an inborn magnetic field that will never diminish. However, this looks quite real when we talk about permanent magnets, as the process of losing magnetic strength is so slow that the magnet takes thousands of years to lose half its strength. For example, SmCo magnets, which are Samarium-Cobalt, may lose their half strength in 700 years.
Do magnets lose strength over time? We will discuss this query later. Let's understand the basics of magnets in a small chunk to get your answer. Magnets are materials with two poles, a south and a north pole which produce a magnetic field around the magnet.
The magnetic field puts a force that either attracts or repels metals like iron and steel. We have two magnet types: electromagnets and permanent magnets. How long do magnets last? Now, let's focus on your question.
What Is Magnetism
Magnetism is caused by all magnetic materials, from nickel and cobalt to iron and certain alloys. It is a physical phenomenon that generates a force around magnetic material through which it attracts and repels the other magnets or charged particles.
The entire region where the magnetic force of a magnet is effective is known as the magnetic field. By nature we have two common types of magnets available.
● Permanent magnets are materials that have magnetism by default.
● Electromagnets are those materials that can be magnetized or demagnetized by using an external influence, like an electric current, whenever a Magnetic field is required.
Magnetic Lifespan
If you are looking for a fixed shelf life of your permanent magnet, you will never find it. There is no shelf life of permanent magnets. We can't predict a fixed number in answer to how long do neodymium magnets last as there are many factors that contribute to magnets losing strength.
Shelf life refers to the period when an item can no longer serve its intended purpose or becomes unsafe to use. Can a permanent magnet lose its magnetism is only possible if it loses a part or all of its capacity to generate an external magnetic field. The extent of this loss would determine how effectively the magnet can perform.
If there is no external influence, the magnetic field of a magnet may be reduced due to "magnetic creep." Magnetic creep is a slow and gradual reduction in its magnetic strength that occurs when a magnet fails to resist its internal forces and starts demagnetizing. This demagnetizing of magnets is known as the permanent magnet self-demagnetizing process. We'll discuss this later.
A well-designed permanent magnet with no external influence will take decades to centuries to get demagnetized properly. However, it's not possible to keep magnets away from external influences when we are using them in various industries.
Do Magnets Wear Out With Use?
Magnets never wear out with use like the other materials do. They just lose a part of their magnetic strength due to various factors which we will discuss below. But with continuous and harsh use in machines and in other industries, there will be a slight decrease in their performance if you can't handle them with care and knowledge.
For a special field or industry, you can make your own customized permanent magnets with the help of some reputable manufacturers like YX Magnetics.
Factors That Contribute To Wearing Out Of Magnet
When it comes to how long will a magnet lasts, the following factors pop into my mind. Although permanent magnets can't demagnetize in simple circumstances, the following factors influence their demagnetizing power.
● Heat: Every magnet material has a maximum heat rating. Placing a magnet at a higher temperature will influence the demagnetizing process and enhance corrosion. When the heat increases, it disrupts the magnetic domain alignment and makes it lose part or all of its magnetic strength. The Neodymium magnets are prone to lose their magnetic strength at higher temperatures.
● Physical damage: Careless handling or mechanical stress can change the magnet's internal structure which results in the loss of magnetic strength. Some magnets like neodymium and ceramic types are brittle and easily damaged by physical impact.
● Moisture: Damage may occur to your magnet housing, allowing moisture to seep inside and causing the magnet material to oxidize. Over time, this oxidation weakens the magnetic system.
● Strong Magnetic Fields: Placing a permanent magnet in an extremely strong magnetic field of any other magnet can initiate demagnetizing, which is known as magnetic saturation. Permanent magnets have strong magnetic fields, but when you put larger and smaller magnets in the same place, the larger ones partially demagnetize smaller magnets. Strontium Ferrite and Aluminum Nickel Cobalt grades are susceptible to magnetic saturation.
Do Magnets Lose Their Magnetism Permanently?
Magnets can lose their magnetism permanently. With time and use, the magnet's magnetic strength starts depleting slowly, eventually taking hundreds of years for complete loss. It all depends upon the material of the magnet, the way it's used, and the environment it is placed.
At the atomic level in permanent magnets, each atom has its own tiny magnetic field which is generated due to the movement of its electrons. These atomic magnets align with each other and form magnetic domains.
When these domains are aligned perfectly they create a strong overall magnetic field. With time and use, the alignment of these magnetic domains becomes disrupted and results in the loss of the magnetic strength of the magnet.
This isn't always a permanent loss but may be reversible. It is possible that some magnets start partial remagnetization. It mostly occurs when the magnet is weakened by heat or a temporary opposing magnetic field.
In such a situation, offering a strong external magnetic field we can realign the magnetic domains to get magnetic strength back. In severely damaged or broken conditions, regaining the original magnetic strength is not possible.
How To Keep Your Magnets From Wearing Out
There are certain ways to keep your magnets from wearing out. You got your answer about how long do magnets last. After knowing the reasons behind this wearing out, it's easy for you to understand that careful maintenance and handling will make your permanent magnets retain their magnetic properties for a longer time.
● Cleaning: The first step is to clean your magnets properly. If you neglect cleaning, dust and debris start accumulating on your magnet's surface and lower its magnetic field and performance. You can use a mild detergent or some soft cloth for gentle cleaning of your magnets.
● Correct storage: When storing magnets, try to choose a clean, dry environment to avoid rust buildup. Positioning magnets so that their poles face in opposite directions can also help preserve their magnetic power.
● Demagnetization Protection: Electric current and strong magnetic fields cause demagnetization of magnets. Avoid placing your magnet in any such environment. Neodymium magnets used in electronics must be kept away from heat as they are susceptible to demagnetization at high temperatures.
● Physical Protection: Physical damage is the most common aspect of causing demagnetization. Use protective cases to lower the chances of physical damage like using a firm rubber casing in an industrial setting to protect the magnets from cracks and chips. Nickel is best for coating while using customized NdFeB magnets in various fields like tech and automobiles. Avoid intentionally dropping or hitting your magnet against hard surfaces.
● Lubrication: In mechanical systems, magnets are used for moving purposes; lubrication prevents rust and wear but should not be used often. Overusing can cause residue buildup, which not only affects magnets but also the overall system's performance. You have to carefully select and apply the lubricant to keep your magnets working efficiently without demagnetizing.
● Avoid High Temperatures: Place your magnets away from the stove and heaters in all temperature-rising or heat-producing areas.
Conclusion
We hope that you got your answer to the question. Do magnets lose their strength over time? Yes, magnets can lose their magnetic strength through demagnetization due to various factors like heat and strong magnetic fields. The process is so slow that it's difficult to notice, like taking hundreds to thousands of years for demagnetization.
But if you follow the right steps to keep your permanent magnets from wearing out, you can further slow down the demagnetization process and keep your magnets functioning correctly.
FAQs
Do neodymium magnets wear out?
Like all other magnets, Neodymium magnets may lose their magnetic strength over a long period. The magnets may lose a fraction of their strength in 100 years if properly cared for and maintained.
Do permanent magnets wear out?
Yes, permanent magnets may lose their strength over time, like 1% in 100 years.
Do rare earth magnets wear out?
Heat and exposure to strong magnetic fields cause demagnetization in rare earth metals. These metals can't wear out like other things, but they lose their performance efficiency due to their reduced magnetic strength.
