How are neodymium magnets produced?
It is very time-consuming to produce super magnets made of neodymium iron boron (NdFeb). Manufacturing takes place in China where the necessary raw materials are extracted as well. Below we will show you the individual steps necessary to produce magnets.
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What is neodymium?Neodymium is a chemical element and belongs to the lanthanides, better known as rare earth metals. It glistens silvery-white and, when exposed to air, oxidises to pink-purple. Neodymium magnets are an alloy of neodymium, iron and boron, as well as other substances. The alloy has the chemical formula NdFeB.
By the way: The alloy NdFeB was discovered in the early 1980s and opened entirely new possibilities for the manufacture of magnets. Thanks to research, new formulations and production methods, neodymium magnets have since gotten a little stronger. That’s how the world’s strongest magnets thus far came about.
Mining and processingThe largest raw material deposits of neodymium can be found in China, where it is mined. For the manufacture of neodymium magnets, it is first extracted from the ore in a complex process. Then iron, boron and other substances are added and smelted to form an alloy. The mixing ratio can affect the corrosion resistance or working temperature of the final product.
Manufacturing and sintering the unfinished castingsThe alloy is slightly magnetised, then cast into a basic shape (usually cylindrical or block-shaped) and cooled. In the next step, the resulting raw ingots are "embrittled", using a special process, where they are milled into a fine powder the size of a few microns. To prevent the powder from oxidizing, this is done in a sealed environment. The powder is then exposed to a magnetic field and shaped under pressure. It is this step of the manufacturing process, that determines the magnetisation direction of the magnets. Subsequent sintering, using high temperature and pressure, densifies the material and shrinks the mass of the magnet. At this point, the resulting magnet resembles its final shape, but its surface is still rough. Its unique crystal structure is ideal for subsequent magnetisation.
Smoothing of the surfaceIn this step of the process, the finished raw magnets are created. The rough surface of the raw magnets is eliminated through grinding and cutting. Due to its hardness, neodymium has to be worked using diamond-tipped tools. To prevent fire hazards, the tools are cooled with water.
Coating the raw magnetsNeodymium-iron-boron oxidises when exposed to the air and is extremely brittle. To make the magnets more durable, they are now coated. The most common coating, namely nickel-copper-nickel (Ni-Cu-Ni), is very thin so that the least amount of magnetic adhesive force is lost. You can find out about other possible coatings on our FAQ page Which coatings exist for magnets?.
Magnetisation and quality controlIn the final step of the production process, the finished magnets are placed into a magnetic coil through which a strong electric current flows for one millisecond. This coil creates a strong magnetic field. The super magnets are magnetised by this magnetic field, meaning the crystal structure aligns with the magnetic field of the coil. Once the coil is switched off, the magnets remain permanently magnetised and pass through a final quality control, where the dimensions, coating and magnetisation are checked.
Great value for moneyAfter a thorough evaluation of various manufacturers, we work with suppliers who offer magnets of consistently high quality at reasonable prices. Since neodymium is one of the rare earth raw materials, it is subject to constant price fluctuations. We manage a large inventory and can therefore place bulk orders with our suppliers at attractive unit prices. In turn, we can directly pass these price savings and high stock availability on to you as a customer.
Additional information about neodymium magnetsIf you want to learn more about neodymium magnets and their characteristics, you will find more information in our FAQ pages.
If you are interested in the origin of magnets and their history, you can find out more in our online guide under The History of Magnets.