{"id":8127,"date":"2020-11-30T14:05:49","date_gmt":"2020-11-30T14:05:49","guid":{"rendered":"https:\/\/monroeengineering.com\/blog\/?p=8127"},"modified":"2024-12-04T15:55:20","modified_gmt":"2024-12-04T15:55:20","slug":"how-are-modern-magnets-made","status":"publish","type":"post","link":"https:\/\/monroeengineering.com\/blog\/how-are-modern-magnets-made\/","title":{"rendered":"How Are Modern Magnets Made?"},"content":{"rendered":"\n
The modern magnet is a manufactured product developed from of a naturally occurring force. The modern magnet is powerful and lightweight. It can be made in high volumes and in unique as well as standard shapes. Science has discovered a number of minerals that increase the strength of magnets and because these minerals are not plentiful and spread all over earth like coal , they are referred to as \u201cRare Earth Minerals\u201d producing \u201cRare Earth Magnets\u201d. Many of these mineral deposits are in Asia and it is there that most magnet production takes place. This dependence on Asia for today\u2019s most common and useful magnets has led to efforts in other countries to develop other minerals and substances that perform as well. Modern magnets are made from a \u201ccocktail\u201d of minerals which can include Iron, Neodymium, Samarium, Cobalt, and Cobalt Nickle. The production process for these \u201cRare Earth Magnets\u201d has historically been patented and then licensed by large corporations like Sumitomo. As these patents expire there may be growth outside of Asia in magnet production. Magnets are so critical to electronic products that their production is considered a strategic interest for most of the world. <\/p>\n\n\n\n
Here is how they are made. <\/strong><\/h2>\n\n\n\n
1. Mined metals are combined in a specific combination then\nmelted into Ingots using a vacuum furnace. The material has no inherent\nmagnetism and is not magnetic at this stage, or only mildly so. <\/p>\n\n\n\n
2. The Ingots are ground into a superfine powder with\ngranules 3 to 7 microns in size. Think of this powder as millions of tiny\nmagnets just waiting to be aligned and energized. <\/p>\n\n\n\n
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3. The powder is put in a press and forced into a shape\nwhile a magnetic field is applied using electrical current. Shapes such as\nrods, blocks, and strips can be produced. The addition of an \u201celectromagnetic\nfield causes all the tiny, powdered granules to align in the same direction\ncreating the \u201cpolarity\u201d necessary for the magnet to work and greatly increasing\nthe force it can exert. While this current is strong enough to align the particles\nour pressed powder Ingot is not yet a magnet. <\/p>\n\n\n\n
4. No matter how much force is exerted the powdered metals\nin the recipe must be heated to just below the melting point to become\ncompletely incorporated into each other. This is known as \u201cSintering\u201d. <\/p>\n\n\n\n
5. The hot metal ingot is then \u201ccooled\u201d by a process known\nas \u201cquenching\u201d. After this point the magnet is extremely hard and brittle.\nFurther processing such as cutting to length, rounding edges for stress relief,\nor making unique shapes takes place. Since the magnet is as hard as carbon tool\nsteel this requires special tools such as diamond tipped cutters and grinders. <\/p>\n\n\n\n
6. Because of being so brittle and prone to rust nearly all\nmagnets are coated. This can be a metal coating like Nickle, rubber, or PTFE\nplastics. A dark magnet is coated with rubber or plastic, a bright one with\nNickle. <\/p>\n\n\n\n
7. Finally the magnet is passed through an electromagnetic\nfield which remagnitized the rare earth minerals. Magnets are typically\n\u201ccharged\u201d to a strength 3 times what the magnet is rated for. <\/p>\n\n\n\n
8. The magnet is then \u201crated\u201d by testing and packaged for\nshipment and sale. <\/p>\n\n\n\n
The industrial process for producing magnets in large\nvolumes is very expensive. The modern magnet is a commercial commodity and they\nare made by the billions. Since these processes are not flexible most magnets\nare made in standard shapes and sizes. The magnet has made the quantum leap\nfrom the Compass which enabled exploration of our Planet in 500 BC, to being a\nkey part of the electronics that allow us to explore the universe and our\nfuture.<\/p>\n","protected":false},"excerpt":{"rendered":"
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