What Can Demagnetize a Permanent Magnet
Temporary magnets, such as paper clips, scissors, refrigerators and staples, easily lose their magnetism. However, permanent magnets, despite being called permanent, can also be demagnetized. The process is called degaussing, and it involves reducing, removing or eliminating the permanent magnet’s magnetic field.
Ways to Demagnetize a Permanent Magnet
When the electrons in an alloyed material are oriented towards a north and a south pole a magnetic field is formed. By disturbing the magnetic field or changing how the electrons align, you can reduce or completely remove the magnet’s magnetic properties. Here are the most common ways to demagnetize a permanent magnet.
Applying heat to a magnet causes increased atomic movement. If you apply enough heat, you can cause the electrons to move out of alignment and disrupt the magnetic field. The Curie temperature is the temperature above which a magnetic alloy completely and irreversibly loses its permanent magnetic properties. It can be as high as 1390 degrees Fahrenheit depending on the materials of the magnet. Varying degrees of demagnetization will begin to occur as the magnet approaches its Curie point.
A collision, such as repeatedly striking it with a hammer or drilling through it, can cause a magnet to lose it’s magnetism. If enough force is applied, it can interfere with the movement of the atoms within the magnet and destroy the north / south pole alignment, demagnetizing the magnet.
Another way to demagnetize a magnetic is by reducing its volume. This can happen by splitting off a portion of the magnet through force, but most commonly happens due to corrosion, erosion or oxidation which can be caused by excess humidity.
Demagnetization can also happen by exposing the magnet to another magnetic field. This is often done by exposing the magnet to a device that produces a strong magnetic field in the opposite direction of the magnet’s, forcing the electrons to realign and lose their original magnetism. Running an AC current near the magnet could also cause lose of magnetism.
Slowly over time a magnet will lose its strength. Exposure to heat, humidity, other magnetic fields, mechanical shock and being dropped happens no matter what. Slowly this will wear down a magnet and cause it to lose its magnetism.
How to Prevent Demagnetization
Proper storage of your permanent magnets is the best way you can prevent unintentional demagnetization. It will help preserve the magnet’s magnetic properties by ensuring they are protected from collision, heat, humidity and other magnetic fields. For more information, read our blog post on proper magnet care and storage.
Another way to make sure your magnets last as long as possible is by using a reliable source for high-quality magnets. At US Magnetix, we provide high-quality products with Ultimate Service. We have a huge selection of industrial magnets available in our online magnet store, or we can help you with a custom order. Give us a call at 763-540-9497 or send us a message online to get started.