3 Top Parameters To Consider When Choosing Rare Earth Magnets
Posted on: 11 November 2019
When choosing rare earth magnets for your application, special care should be focused on the selection process. Whether you need a lifting magnet for a car junkyard business or a detecting pick, the right choice will go a long way in improving your business operations. That said, there are various considerations you must pay attention to when evaluating rare earth magnet options. This write-up offers a detailed guide on these parameters.
Heat Resistance
Magnetic strength of a rare earth magnet is affected by changes in temperature. As such, the first and probably the most critical parameter you should look at is the temperature of the application. While some rare earth magnets perform under low temperatures, others do exactly the opposite. For instance, neodymium magnets still retain their flux until the temperatures hit 100 degrees Celsius. Above these temperatures, neodymium magnets begin to lose their flux, thereby rendering them useless in some applications. On the other hand, ferrite rare earth magnets lose part of their flux in environments below -40 degrees Celsius and above 150 degrees Celsius. Therefore, it is imperative to know the operating temperatures of the environment within which you'll be using the magnets.
Availability
As their names suggest, rare earth magnets are not that common, especially if you consider that they are labour-intensive to extract. Moreover, the production conditions of rare earth magnets must be tightly controlled to maintain the materials' purity. Therefore, it is essential to find out the availability of the type of magnet you want for your applications. While some rare earth magnets are a problem to source based on geographic limitations, others like neodymium magnets are not that rare. For example, China produces a significant amount of rare earth oxides, metals and alloys, which are used to enhance the magnetic strength of rare earth magnets. Therefore, sourcing should not be much of a problem since you know exactly where you are getting the magnets and the quality you are getting.
Magnetic Output
Different applications require magnets with varying strengths. For instance, lifting magnets used in car junkyard will be many times stronger compared to magnets used to separate metallic objects from oil. The strength of a magnet can be quantified using two metrics. The first metric is residual induction, which is the force required to remove a permanent magnet placed on a block. Maximum energy product is the second vital metric, and it is essential in the calculation of motor performance. Therefore, the higher the magnetic output of a magnet, the more the lifting capacity.
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