The Diference between each Peramenent Magnets
When purchasing magnets you will see two major types, rare earth or ferrite magnets. Sometimes, under the rare earth magnets, there are sub types like neodymium or samarium. Alnico is another type of magnet you might see listed. Rare earths tend to me more expensive, but why? What’s the difference between magnets?
Here are some of the defining properties and differences:
Ferrite Magnets, sometimes referred as ceramic magnets, are generally the most common and cheapest of all the magnets. These magnets are created by combining a compound called iron-oxide with another ceramic type material like barium. They are cheap, common materials that allow low cost permanent magnets to be built. Since they are ceramic, that also makes them very durable in most environments. Generally speaking, ferrite magnets are easy to work with and since they are ceramic, they are resistant to rusting or other types of corrosion.
Unfortunately, the good part of the ceramic is also coupled with the bad; they tend to have a low mechanical strength and are brittle. These types of magnets are perfect for use on your refrigerator or steel doors. They also work well in high temperatures so could be used in garages or basements that don’t see a lot of air conditioning.
Alnico Magnets is a mash-up of the words aluminum, nickel and cobalt; the three main materials used in their creation. Unlike the ferrite magnets, these magnets are a true metal alloy. They are strong, can be molded like steel into a variety of shapes. They are quite resistant to drops and falls and will not crack or break easily. Nickel and cobalt happen to be metals that are used in stainless steel, which means that Alnico magnets are also highly resistant to corrosion.
These magnets are expensive to produce though, which means that they will come at a higher end user cost. They are also of a moderate strength, so keep that in mind if you want to use them in a high magnetic power type of situation.
Samarium Magnets is a rare earth metal that when combined with cobalt produces a very powerful magnet. These magnets are rather expensive to produce, but the high cost brings a very high power magnet. They are also resistant to corrosion and rusting and work well in extreme temperatures. While not ceramic, they are rather brittle and not as resistant to drops and falls as Alnico magnets are. Care must be taken not to damage them.
Neodymium Magnets are the most common of the rare earth magnets, these are made of a rare earth metal called neodymium that is combined with Iron and Boron. While similar in power to the Samarium magnets, neodymium is not as resistant to rusting and corrosion as the samarium or alnico magnets are. The trade-off is in the power. Neodymium magnets are the strongest of the types we’ve talked about and can be used in a variety of high power magnet applications. They are not as resistant to temperature as some of the other magnets, and if they are not coated can be affected by temperature and corrosion. Care and maintenance must be taken to ensure optimum operation. Send RFQ to UMAGNETS Now!