Switching From Ferrite Magnets to Rare Earth Magnets
Switching from traditional ferrite magnets to rare earth magnets is no small thing. Magnets are measured by their BHmax score. The higher the number the stronger the magnet. Most traditional ferrite magnets will have a BHmax of no higher than 3.5. A rare earth magnet can have a BHmax of up to 40, more than ten times stronger! Any time that you have a jump of power like that you will need to carefully consider how to implement it.
The best thing about this switch is that you can manufacture your products much smaller and lighter. With the higher BHmax score you will need less material, less packaging around it and less space in general. You should think about whether or not there will be a cost reduction that is comparable.
Your decision making process should be concerned with the improvements in performance, the cost involved with obtaining that performance, the reduction in power consumption and how that affects the systems around it and any other factors that this conversion will put on the product as a whole.
Something that may escape some people is that the electrical conductivity of rare earth magnets is very large when compared to other types of magnets. This comes into play greatly in motors and generators where heat can be generated due to the altering of the magnetic field due to the moving parts.
II. Ferrite Magnets
Ferrite magnets, also known as ceramic magnets, are made from a mixture of iron oxide and other metallic oxides. They have been widely used for many years due to their low cost, high temperature stability, and good corrosion resistance. Some common applications of ferrite magnets include speakers, headphones, and small electromagnets.
However, ferrite magnets have several drawbacks, including low energy efficiency, low magnetic strength, and a relatively large size for a given magnetic field. These limitations have led to the development and adoption of rare earth magnets as a more suitable alternative.
III. Rare Earth Magnets
Rare earth magnets, on the other hand, are made from a group of 17 chemical elements, including neodymium, samarium, and dysprosium. These magnets exhibit much higher magnetic strength and energy efficiency compared to ferrite magnets. As a result, they have become the preferred choice for applications requiring strong magnetic fields and compact size, such as electric motors, wind turbines, and magnetic levitation systems.
One of the main advantages of rare earth magnets is their high energy efficiency, which means they can produce stronger magnetic fields with less input energy. This has made them ideal for use in electric vehicles, where motors require powerful magnets to achieve high torque and efficiency.
Another benefit of rare earth magnets is their environmental friendliness. Ferrite magnets contain toxic metals, such as lead, which can be harmful to the environment if not disposed of properly. In contrast, rare earth magnets are made from non-toxic elements and can be recycled, making them a more sustainable option.
However, rare earth magnets do have some drawbacks. They are more expensive than ferrite magnets and can be more challenging to work with due to their brittleness. Additionally, the production of rare earth magnets requires the mining of rare earth elements, which can have negative environmental impacts and raise ethical concerns.
IV. Factors Contributing to the Shift
The shift from ferrite magnets to rare earth magnets has been driven by several factors, including advancements in technology, increasing demand for energy-efficient products, and environmental concerns. As mentioned earlier, the higher energy efficiency and magnetic strength of rare earth magnets have made them the preferred choice for many applications, such as electric vehicles and wind turbines.
Furthermore, the increasing demand for energy-efficient products has led to a growing interest in using rare earth magnets in various industries. This has resulted in a higher demand for these magnets, which has driven down their prices and made them more accessible to a wider range of applications.
Lastly, environmental concerns have played a significant role in the shift towards rare earth magnets. The toxic nature of ferrite magnets and the environmental impacts of mining rare earth elements have led to a push for more sustainable and eco-friendly alternatives. Rare earth magnets, being non-toxic and recyclable, are seen as a more environmentally responsible choice.
The adhesion choices you make are important because the thermal expansion rate of rare earths are vastly different from ferrite magnets. It is critical that you choose the right adhesive to match where and how the magnet is being used to minimize issues during regular use.
A use that is sometimes overlooked is as advertising. Magnetic rolls and sheets are often used for this purpose, but a strong rare earth magnet holding up you advertising, or handed out as a promo, is a sure way to get some attention!
Contact us at MPCO Magnets if you need any help sorting through these issues. We would be glad to help you!