What Is A Neodymium Magnet Made Of?
Neodymium magnets are made from an alloy of neodymium, iron, and boron (NdFeB). Magnets made of neodymium are often called 'super magnets' because they have the highest adhesive force in the smallest space. The typical composition of a Neodymium magnet is about 65-75% iron, 15-20% neodymium, and 1-5% boron. Small amounts of other elements such as dysprosium, praseodymium, and cobalt may be added to enhance specific properties like temperature resistance and coercivity. The exact composition of a Neodymium magnet can vary depending on the desired magnetic characteristics and the intended application of the magnet.
Do Neodymium Magnets Come In Different Shapes And Sizes?
Neodymium magnets come in various shapes and sizes to suit different applications, from tiny disc magnets used in delicate electronics to large block magnets so big they can lift cars and industrial equipment. Disc magnets are circular magnets with a flat, disc-like shape. They are commonly used in motors, sensors, closures, and magnetic therapy devices. Block magnets, also known as rectangular or bar magnets, have a cuboid shape and are used in magnetic assemblies, lifting applications, and magnetic separators. Ring magnets have a round shape with a hole in the centre. They are often used in loudspeakers, magnetic bearings, and jewellery clasps.
Sphere magnets are spherical magnets that are used in educational toys, experimental setups, and artistic installations. Cylinder magnets have a cylindrical shape and are used in various applications, including magnetic closures, jewellery clasps, and sensors. Arc magnets have a curved shape and are commonly used in motors, generators, and magnetic assemblies where a curved magnetic field is required. Cube magnets have a cubic shape and are used in educational demonstrations, experimental setups, and craft projects. These magnets have a flat top with a countersunk hole, allowing them to be easily mounted using screws or bolts. They are commonly used in magnetic holding and mounting applications.
Neodymium magnets can also be custom-made into various shapes and sizes to meet specific application requirements. Custom shapes may include irregular shapes, special contours, or tailored dimensions. These different shapes allow neodymium magnets to be versatile and adaptable to a wide range of applications across various industries.
What Are Neodymium Magnets Used For?
Neodymium magnets are used in a wide range of applications due to their exceptional magnetic properties. From huge industrial processes to jewellery and domestic uses such as humble door and cupboard latches, these powerful magnets have become an essential component of modern daily life. Here are just some of the ways Neodymium magnets are utilised.
Neodymium magnets are used in electric motors and generators for various applications, including automotive, industrial machinery, and household appliances. They are used in magnetic separation equipment to remove ferrous contaminants from materials in industries such as mining, recycling, and food processing.
Neodymium magnets are crucial components in loudspeakers and microphones, providing high magnetic strength for clear and powerful sound reproduction. They are used in magnetic bearings and couplings for rotating machinery, because they create a frictionless and maintenance-free operation.
Neodymium magnets are used in MRI machines for medical imaging due to their strong and uniform magnetic fields. Because they have incredible power to size magnetic properties, Neodymium magnets are used in various sensors for speed sensing, position detection and proximity sensing in automotive, industrial, and consumer electronics applications.
Neodymium magnets can be extremely small and yet still very strong, making them ideal as magnetic clasps for jewellery, handbags and clothing closures. They can be attached to delicate fabrics and surfaces without being visible and their diminutive size and strong magnetic hold means they can be inserted or attached to garments, jewellery and accessories without detracting from the overall appearance of the item.
Neodymium magnets are used in therapeutic devices such as magnetic bracelets, wraps and mattresses for pain relief and improved circulation. Neodymium magnets are incredibly versatile and can also be used in industries as diverse as wind turbine generators, where they are used in the process to convert wind energy into electrical power efficiently. Neodymium magnets are used in robotics and automation systems for gripping, lifting and positioning applications. The applications where Neodymium magnets can be used are almost limitless. Their high magnetic strength, compact size and cost-effectiveness makes them an increasingly essential component in a growing number of industries and applications.
Are Neodymium Magnets Dangerous?
They can be if they are not used correctly. Neodymium magnets are extremely powerful and due to that strong magnetic force, these magnets can pinch fingers, cause injuries, and affect electronic devices if not handled properly. The best way to handle Neodymium magnets to avoid injury involves several precautions. It's a good idea to wear gloves to protect your hands from pinching or cuts if you are using some of the larger Neodymium magnets. Always maintain a safe distance between large magnets. Handle Neodymium magnets one at a time and keep them away from other magnets and metal objects to prevent sudden, forceful attraction and it's a good idea to use a non-magnetic surface for working with them.
Make sure you keep Neodymium magnets away from electronic devices and magnetic storage media, as strong magnetic fields can damage them and affect their performance.
Small Neodymium magnets can pose a real risk to children as a swallowing hazard. Never let young children play with small magnets and check toys that have magnets in them to make sure they are secure, check that the magnets won't fall out of the toy and there is no access to the magnet.
Use caution when separating magnets. Best practice is to slide them apart instead of pulling directly to minimise the risk of snapping together. Make sure you store magnets securely in containers to prevent accidental injury or damage.
Why Are Neodymium Magnets Called Rare Earth Magnets?
Neodymium magnets are called rare earth magnets because they are made from rare earth elements, which are difficult to extract and refine. A rare earth magnet is made from alloys of rare earth elements, known for their exceptional magnetic strength. These magnets are the strongest available commercially, much more powerful than other types of permanent magnets like ferrite or alnico magnets. There are 17 rare earth minerals in the Lanthanide series of metals in the periodic table. The two most common rare earth magnets are neodymium (Nd-Fe-B) and samarium cobalt (SmCo).
Despite the name, rare earth elements are actually abundant in the Earth's crust but are called 'rare' because they are not frequently found in concentrated deposits and are mixed in with other elements. The process of extracting rare earths is economically challenging due to low concentration of rare earth ore deposits among those other elements, and the high-tech requirements to obtain pure rare earth materials from that process. As a result, only a few sources provide most of the world’s supply of rare earth elements.
How Long Do Neodymium Magnets Last?
Neodymium magnets have a very high coercive force and are known for their long-lasting magnetic properties. These magnets do not easily lose their magnetic properties over time if kept in appropriate conditions. Under normal conditions, Neodymium magnets can retain their magnetism for many decades. The loss of magnetic strength over time is minimal, often less than 1% over ten years, as long as they are not subjected to factors that can accelerate demagnetisation. Exposure to temperatures above their maximum operating limit, usually between 80°C to 150°C, depending on the grade, can cause permanent loss of magnetic strength. Cracking, chipping, or breaking can occur if the magnets are handled roughly or dropped, and that damage can affect their performance.
Corrosion can also damage a Neodymium magnet. Although many Neodymium magnets are coated to prevent rust, prolonged exposure to moisture or corrosive environments can still degrade their magnetic properties over time if the coating is damaged. Exposure to strong opposing magnetic fields can also partially demagnetise Neodymium magnets.
Despite the sensitivities to corrosion, high heat and impact damage, Neodymium magnets can maintain their magnetic properties effectively for a very long time, making them reliable and essential for countless applications.