Scientists have long been trying to create super-strong magnets based on various alloys. But in most developments, it was necessary to use materials that could be dangerous to humans. Finally managed to get a composition based on neodymium. This rare earth metal does not pose a potential he alth threat. Having become acquainted with the unique properties of such a material, many are wondering whether it is possible to make neodymium magnets with their own hands. According to the idea, this is a technologically complex process. Or can it be made from recycled materials?
Neodymium magnets: what is this material?
According to scientists, this development took about 20 years of research and testing. When choosing materials, many factors were taken into account: availability, manufacturability, safety, high magnetic properties, resistance to environmental conditions. Scientists considered the use of rare earth metals as a promising direction. And neodymium was just perfect for these purposes.
Magnets based on it have amazing adhesive power. Even a small amount of material allows you to keep the weight inmany times its own weight. Magnetic properties are retained for a long time (lose no more than 2% over 10 years of use). Now neodymium magnets can be purchased in specialized stores. Their prices are available to almost anyone.
Composition
Magnets based on this rare earth metal are denoted by the formula Nd2Fe14B. The composition includes neodymium (Nd), iron (Fe), boron (B). The peculiarity of the technology lies in the fact that this rare earth metal in its pure form is difficult to isolate. The sintering process with the remaining components in powder form must take place in an inert environment. Otherwise, it rapidly oxidizes with loss of properties.
Technology for normal conditions is complex, so trying to make neodymium magnets with your own hands is impractical. Products are marked during production. The number after the letter N (25, 30, 45) indicates the code. The higher the index, the stronger the magnetic properties of the material. The maximum operating temperature of the magnet also depends on the number.
Features
To prevent from exposure to environmental conditions, the magnets are coated with a protective compound. Usually these are two layers of nickel or an improved version with an additional layer of copper in between. Another important feature is that neodymium magnets begin to demagnetize at temperatures above 70 ° C. Exceeding the limit values can lead to a complete loss of properties and the transformation of the alloy into just a piece of metal.
The specificity of the material implies special safety measures when working. So, neodymium magnets 50x30 mm have an adhesive force of 100 - 115 kg, and 70x50 mm up to 300 kg. If handled carelessly, they can cause harm: pinch fingers, injure the skin, damage the bone. If two magnets collide uncontrollably, the material may crumble and form sharp fragments that can injure the eyes.
Application
Traditionally, they are used in electronic devices and devices where it is necessary to create a constant magnetic field. The properties of the material make it possible to successfully use them when searching for and lifting metal objects from the bottom of reservoirs. Such structures, in addition to the eye for attaching the cable, are equipped with an eyebolt, which is simply necessary, since when screwed in, it allows you to disconnect two strongly interlocked surfaces.
Magnets are available in sizes from 1 to 120 mm in diameter and in different thicknesses and shapes. The thinnest of them are widely used in the leather goods and furniture industries. They can be found in funny toys and devices for hanging various utensils. Powerful magnets are indispensable for filtering loose and liquid materials. They are used to trap metal impurities and foreign objects in the conveyor stream.
The high traction force encourages people to use them for "savings" on water and gas as well. By purchasing neodymium magnets for counters, they are thus trying to stop or slow down the rotation of their mechanism. This possibility is theoretically available in deviceswhere steel elements are used inside. A powerful magnet placed in a certain place on the casing can slow down the rotation of the impeller.
Can I make my own neodymium magnets?
Industrial technology, in addition to sintering the mass into an alloy, also involves a complex and inaccessible for home conditions process of magnetization of the resulting substance. For this, very powerful force fields are used. If there is a great desire to get neodymium magnets yourself, you can do it yourself by disassembling the "obsolete" electronics.
In some old hard drives you can find one or two small elements inside. Trying to drill or crush such magnets is impractical. The surface protective layer is damaged, the material reacts with the medium and loses its properties. In addition, according to experts, the chips are highly flammable and can ignite surrounding surfaces.
