Rare-earth magnets, including samarium-cobalt and neodymium-iron-boron (NIB), offer prized for their superior strength and performance. They live up to their namesake by featuring a construction of rare-earth elements that are capable of producing exceptionally strong magnetic fields. You can find rare-earth magnets in everything from kid’s toys and electronics to manufacturing machines and equipment. Below are several fun facts about rare-earth magnets.
#1) 2 to 3 Times Stronger Than Regular Magnets
In terms of magnetic strength, rare-earth magnets are about two to three times stronger. The strength of a magnetic is usually measured in the tesla. While standard magnets, such as ceramic magnets, produce about 0.5 tesla, rare-earth magnets produce about 1.5 tesla, making them up to three times stronger.
#2) Developed in the 1960s
Rare-earth magnets are a relatively modern invention. Their origins can be traced back to the late 1960s, during which researchers at the US Air Force Materials Laboratory discovered the magnetic properties of yttrium and cobalt. In the years, manufacturing companies took notice of rare-earth magnets, and it wasn’t long until they found their way into common consumer and business products.
#3) Heat Resistant
You might be surprised to learn that rare-earth magnets are heat resistant. All rare-earth magnets have an inherently greater level of protection against heat than standard magnets. Some rare-earth magnets, though, are more heat resistant than others. Samarium cobalt rare-earth magnets, for instance, can withstand temperatures in excess of 550 degrees Fahrenheit without losing their magnetic field.
#4) Prone to Corrosion
Although they are strong, rare-earth magnets aren’t without flaws. Rare-earth magnets, for instance, are prone to corrosion. When exposed to moisture and oxygen, they begin to corrode. The good news is that additives can be used to increase their resistance to corrosion. Neodymium rare-earth magnets are often coated with gold, zinc or nickel, which creates a protective layer to discourage corrosion.
#5) Longer Lasting
All magnets will lose some of their magnetic strength over time. Rare-earth magnets, however, aren’t susceptible to the same age-related loss of magnetic power as other magnets. A standard magnet may lose about 5% of its strength per 100 years, whereas rare-earth magnets lose just a fraction of this amount.
Contrary to what some people believe, rare-earth magnets aren’t particularly expensive. Up until the 1990s, they did come with a high price tag. Recent advancements in manufacturing, however, have paved the way for faster and more efficient production cycles. As a result, rare-earth magnets cost significantly less today than they did in the past.