Neodymium magnets, what are they and what are they for?
Many people ask about neodymium magnets, what they are and what they are needed for. Well, check out the review, here you will find out where magnets are used, how they appeared and where it is better to buy. Hurry up and move on!
Each of us knows what a magnet is. But if you ask about neodymium magnets, what they are and what they are for, not everything will be answered. If you are not yet familiar with this “miracle beast,” then read on. Just imagine, the first such magnet was invented in 1983 by accident and in 3 laboratories at once!
If you think about it, this is more like a myth, but the surviving documentation confirms the fact that the neo-magnet recipe was created in three points on the planet at once. Unimaginable!
General Motors - an American company, Sumitomo Corporation - a Japanese trading company and the Chinese Academy of Sciences were able to make a breakthrough in the magnetic industry.
What are neodymium magnets and what are they for?
Such products have a powerful magnetic field. The composition is very interesting, there are only three components: boron, iron and neodymium. The latter, in turn, is a rare earth element. More precisely, it belongs to the rare earth class, but there is quite a lot of it on planet Earth.
Do you know how to choose a neodymium magnet for a water meter? No?! Rather, go to https://inforemontik.ru/kak-podobrat-neodimovyiy-magnit-dlya-schetchika-vodyi/ where complete instructions await you.
These magnets are known for their attractive force and good resistance to demagnetization. In appearance they resemble an ordinary magnet, only with a characteristic metallic sheen (on a fault it is no different from the usual version of the magnet).
The production of neodymium magnets is a separate topic, but we will briefly touch on it. There are two methods: baking and injection.
For baking, a ready-made mixture is used, it is shaped and sent to an oven heated to 1200 degrees, or it is injected into molten polymer, and then poured into molds.
Pricing is the main problem when buying and selling this product. According to statistics, 95% of neodymium is mined in China and additional export quotas limit wasteful treatment of it.
Because of this, the first jumps in value began to show themselves back in 2009, then in 2011. the cost of neodymium has increased 5 times. And 2017 raised the price by another 1.5 times.
Where is the best place to buy?
Buying neodymium magnets is not an easy task. There are a large number of fakes on the Russian market. Why not order from China?
Source: https://yerkramas.org/article/149704/neodimovye-magnity-chto-eto-i-dlya-chego-nuzhno
What a neodymium magnet can do in everyday life - we reveal all the secrets
Neodymium magnets have now firmly replaced simple ones. They are made from NdFeB metal alloy, which has excellent magnetic properties. Result: the device is better magnetized and much more resistant to demagnetization, unlike the usual one.
We will consider what can be made from a neodymium magnet in the material.
Areas of application of neodymium magnets
The first thing that comes to mind is the production of toys and puzzles from this alloy. As a rule, for these purposes, not the strongest magnet is used, which is produced in the form of balls. Crafts made from magnets can be formed into various shapes, and complex sculptural forms in miniature can be formed from neodymium. But it is important to remember that such a toy is prohibited from being given to children under 6 years of age.
A pair of magnets placed in the stomach or intestines can hook the walls of the esophagus, which in turn will lead to perforation, and the victim will inevitably end up in the hospital.
You can make various fasteners from a magnet with your own hands. A pair of medium-sized magnets can be used as a vice. The use of an alloy, in this case, is much more practical, in contrast to a vice made of ordinary metal. Parts of non-standard shapes will be fixed more reliably.
For car enthusiasts, this alloy is generally irreplaceable and can be used in a wide variety of ways. For example, not everyone knew that a magnet can be used to filter oil in an oil filter.
If you install it on the drain plug in the engine crankcase, then all metal debris will accumulate at the installation site, which will subsequently make it easier to remove.
Using magnets, it is convenient to search for small metal objects, such as needles or pins on a fleecy carpet. Neodymium can be used to search for metals in the ground or various communications in walls.
The device is suitable for magnetizing various steel objects, such as screwdrivers, needles and more. With its help, a tool or other steel equipment is fixed. Properly installed magnetic holders will help you organize your tools correctly in the workshop or even in the kitchen.
In addition, an alloy of such power can magnetize even an old demagnetized magnet.
It is often used to format information on electronic media.
Information from video and audio cassettes, as well as from the hard drive and from credit cards, is permanently deleted using a powerful magnetic field.
Options for using magnets in everyday life
Neodymium magnet is widely used in everyday life. The main thing is to be able to show your imagination. There are both standard methods and very interesting applications.
Amazing spice rack
To ensure that spices are always at hand and do not take up much space, you can design a special shelf using neodymium. For this you will need:
- Metal jars with a transparent lid.
- Neodymium magnet with a diameter of 1.5x6 mm.
- Epoxy resin.
- 100 grit sandpaper.
We sand the bottom of the jars on the outside and use resin to attach magnets. After this, they will stick securely to any metal surface.
Life hack: you can create a metal surface yourself. Simply attach a metal plate to a regular covering. If it is missing, use what you have. For example, the refrigerator door. At the same time, we recommend that you familiarize yourself with the master class on creating refrigerator magnets with your own hands without dust and worries.
It turns out beautiful and neat.
Scissors and household tools at hand
Knives, scissors and other household utensils can also be attached to neodymium clamps. To do this, just choose a suitable place, create a strip of magnet and install it. And then kitchen utensils will always be at hand.
By the way, you can use magnets from speakers for this, the main thing is to design them beautifully.
Beer storage method
Source: https://ShkolaPodelok.ru/iz-drugih-materialov/chto-mozhno-sdelat-iz-neodimovogo-magnita.html
Where are neodymium magnets used?
Magnets continue to gain popularity. They are used in an extremely wide range. To a greater extent, magnets are used today in the field of creating souvenir products.
However, neodymium magnets have outstanding characteristics that cannot always be applied legally.
Advantage of neodymium magnets
First of all, it is worth noting that neodymium magnets are the best magnets that can be produced today. They do not demagnetize even after 100 years. In addition, neodymium has no equal in terms of the strength of creating a magnetic field!
Neodymium magnets are often called as follows:
- super magnet;
- absolute magnet;
- best magnet
- magnet for braking meters.
If you see marked positions somewhere, it means they are selling you a neodymium magnet. In addition to itself, the magnet contains a small part of iron, as well as boron.
Neodymium magnets are widely used for fastening various elements. Magnetic fasteners vary in the weight they can support. You can find options that can even hold curtains with curtains.
The strength of a magnet largely depends on the concentration of neodymium in its body, as well as on the very dimensions of the magnetic body.
The impact of magnets on health, as well as administrative offenses
Traditional science has proven that neodymium magnets (of any strength) are absolutely safe for the human body. Some even believe that magnets may be useful in the treatment of certain psychological diseases or in the treatment of migraines.
However, there is no hard evidence for this.
In addition, in everyday life, strong neodymium magnets are often used to effectively brake meters (electricity, water).
It must be emphasized that this is a violation of the law. If the controller finds out that a magnet was used, a very significant fine will be issued (This is the best case scenario. It all depends on the volume of fraud).
For a long service life, neodymium magnets are protected with a special coating (zinc, nickel, etc.). If you intend to use the magnet in a humid environment or in temperatures exceeding the threshold of 100 degrees Celsius, it is highly recommended to use nickel-plated magnets. Galvanized ones can quickly become unusable.
Also watch the video on how to safely disconnect strong neodymium magnets.
Source: https://euroelectrica.ru/gde-primenyayutsya-neodimovyie-magnityi/
Why are magnets used on license plates?
The dream of every driver is to never receive a fine. With the development of technology, when the streets are equipped with all-seeing cameras, it becomes much easier to catch violators - which means that ways to bypass video surveillance and protect themselves from punishment are being developed.
One of the latest innovations in the automotive world is a magnet, which is placed directly under the license plate. The device helps to hide certain parts of the state sign, thereby making it impossible for street cameras to record it.
Why do you need a magnet and how does it work?
For many, a magnet for a number is a trinket with a primitive structure.
In fact, the device is the most reliable and effective way to hide a number.
The magnet itself is installed under the license plate, and a metal plate that covers several symbols of the license plate is placed on the front side. You can control the operation of the device while in the cabin, since its power is connected to the car's electrical network. The magnet is activated by pressing the remote control button. At the same time, it creates a magnetic field, which holds the plate covering a certain part of the number.
When turned off, the magnetic field disappears and the plate simply flies onto the road. If an inspector stops a car, it will not be possible to prove that the driver deliberately hid the license plates.
Where to buy and how much it costs
There are many options where you can buy a device with a magnet, from automotive markets to online stores. The cost of the kit can be up to 1 thousand rubles.
You need to understand that you cannot save on such mechanisms, but you should not overpay too much, because the device itself does not have expensive components. Car accessories stores sell magnets at a cost of up to 4 thousand rubles. In turn, when ordering on the Internet, you can see the cost of up to 2 thousand rubles.
Real penalties for a magnet
If the camera fails to recognize a license plate with several hidden characters, no fine will be charged. However, the situation is completely different if the sign is hidden when stopped by inspectors. If a car owner forgets to turn off the device or the mechanism does not work, problems may arise.
According to the law, for intentional or unintentional concealment of car registration data, a fine is provided, the maximum amount of which can be 5 thousand rubles. Also, for installing a magnetic device, the driver may lose his driver's license for several months.
Today, a number magnet is a great way to save your finances. But we should not forget that violating traffic rules can cost the health and even lives of road users - and then it will not matter at all whether the camera recognized the license plates.
Source: https://moyidorogi.ru/dlya-chego-ispolzuyut-magnity-na-nomerax-avto/
What are neodymium magnets used for?
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In principle, there are no more effective options than neodymium magnets. No ferrites can even come close in terms of magnetic characteristics. Just think, a 5-ruble coin, which is made of a neodymium magnet, can hold almost 9 kg of weight!
Where are neodymium magnets used?
Below are the most notable industries:
- electronics;
- toys;
- equipment (wind generators);
- everyday life
Neodymium magnets should be used with extreme caution in everyday life. The fact is that they have an incredible power of attraction. If you attach a magnet to a metal surface, you will hardly be able to even move it, let alone remove it.
Meanwhile, neodymium magnets are actively used in interior design. For example, in the bathroom there are a large number of communications (pipes) that need to be hidden to ensure the attractiveness of the room.
This can be done using plasterboard niches. But any plumber will confirm that bricking even into drywall is strictly prohibited by the rules.
However, a niche can always have a hatch that can be completely removed. This hatch is held in place by neodymium magnets (small in size).
Neodymium magnets in the form of a toy
You can find information online that says neodymium is an unusual metal that can heal and protect. Needless to say that this is just another nonsense of marketers (we all remember the zirconium bracelets that Buba Kikabidze tried to sell to us)?
However, neodymium magnets cannot be faulted for their beauty. It is a gray metal that can have a bright shine and can really be used to create attractive jewelry.
In addition, neodymium has recently begun to be used in the toy industry. Naturally, small balls are also used there, since the larger the dimensions of the magnet, the greater magnetism it has.
There should be no risk of injury. Meanwhile, even if magnets with two coins are placed above and under your hand, it is quite likely to get injured (bruises will form where the magnets touch).
The video will demonstrate various practical applications of neodymium magnets:
Source: https://glavspec.ru/dlya-chego-nuzhnyi-neodimovyie-magnityi.html
Neodymium magnets: what are they?
December 14, 2019
Neodymium magnets are characterized by very high power and resistance to demagnetization. They appeared relatively recently, a little less than 40 years ago. They quickly gained popularity due to their high magnetic induction. Even magnets of small mass can provide very high adhesive force. For example, a neodymium magnet in the form of a cube with an edge of 10 centimeters will provide an adhesion force of 4.5-5 kg, which cannot be compared with traditional magnets.
In addition, they have other properties that are extremely useful. They lose from 0.1 to 2% of magnetization in 10 years (during this time any ordinary magnet will demagnetize almost completely). That is, under ideal conditions, neodymium magnets can last several thousand years. But this is in theory, in practice the real terms are up to a hundred years or more. But this is still a lot when compared with conventional magnets.
They also have certain disadvantages that make their use somewhat limited. Firstly, they are susceptible to corrosion, to prevent which they are coated with nickel (but not all). They cannot be heated, and the maximum permissible temperature depends on the brand:
- EH – up to 200 degrees;
- M – up to 100;
- N – up to 80.
They are fragile, you should avoid any mechanical impacts, let alone falls from a height. They can also negatively affect the performance of electronics. Although, because of this property, they are used for not entirely legal purposes, which we will write about below.
It is worth noting that the disadvantages include their price, which is very high (compared to conventional magnets). They especially began to rise in price recently, after China introduced export quotas for rare earth metals. China contains more than 50% of neodymium deposits, which is the main component of magnets. Obviously, this trend will continue in the future, so neodymium magnets will become more expensive.
They are produced in various shapes and sizes: disks, cubes, rods, balls and others. Some products are capable of lifting masses weighing more than one ton.
Neodymium magnet for stopping meters: which one is needed
Many common models of water and electricity meters have rotating metal parts inside, which can be influenced by the magnetic field of a neodymium magnet in such a way as to slow down their operation and reduce the final readings.
Before recommending magnet models for stopping meters, let us remind you that such influence on the meter is illegal and, if detected, is punishable by a fine and recalculation of consumption for the period of operation of the magnet. With a high degree of probability, you will simply lose a lot of money.
However, we will consider the theory (this can also be used for other purposes that do not involve deception or harm).
The main characteristic of a magnet is its power, which depends on the size of the product. It is important not only to choose a sufficiently powerful magnet, but also not to buy one that is too large so as not to affect your neighbors’ meters. One of the recommended brands of neodymium magnets is Rexant.
What kind of neodymium magnet is needed to stop water meters:
- For the simplest models: Metron, Neva, Gerrida, a 45x15 mm magnet is suitable;
- For Novator, Minol, Betar, Norma, etc. you need a larger magnet - 50x20 or 50x30 mm;
- Valtec, Itelma, Meteor and the like - magnet 60x30 mm;
- Elster - magnet 70x40 mm;
- For heat and water meters - magnet 70x50 mm
What kind of neodymium magnet is needed to stop electricity meters:
An electric automatic meter cannot be stopped in this way, but for mechanical models the recommendations are as follows:
- Mercury 201-203, Mikron SEO, Neva, SKAT 101 - magnet 50x20 mm;
- Meridian, Energomera - magnet 45x30 mm;
- Mercury 230-231, Micron PSCH, NIK, STE - magnet 50x30 mm;
- SKAT 301 - magnet 60x30;
- CA4, SO, SOLO, ESR powerful magnets 70x30 and 70x50 mm are suitable.
Why are neodymium magnets needed?
Magnets made from an alloy of rare earth neodymium, boron and iron are widely used both in industry and in everyday life.
Due to the fact that neodymium magnets create a more powerful field than conventional ferrite ones and are also more resistant to demagnetization, they are used for the production of generators, electronics (headphones, computer hard drives), magnetic resonance imaging scanners and much other equipment.
Quite often, ordinary people ask why neodymium magnets are needed in everyday life. And it turns out that in this area there are a lot of ways to use them.
- search and lifting of metal objects: a key at home or on a property is lost, or a bucket has fallen into a well - a neodymium magnet will solve these problems;
- fixing objects when gluing: 2 magnets are attached from different sides and provide uniform and constant compression;
- fastening metal objects in the kitchen or garage;
- securing signs, plates, navigator or radio remote control and other similar items in cars;
- destruction of data on magnetic media: if you need to securely delete information from old cassettes or floppy disks;
- from a couple of magnets you can make excellent latches for furniture and save yourself from the need to screw in screws;
- such magnets will simplify the collection of metal debris (for example, shavings);
- This is an excellent material for visually explaining to children the effects of a magnetic field.
In addition, you can find many reviews online about the use of neodymium magnets to magnetize water (which some claim improves its properties), condition fuel (and save it), and even accelerate the maturation of wines and liqueurs.
Whether to believe that neodymium magnets are needed for these purposes is a personal choice. These facts have not been scientifically confirmed, and our people believe in many things that have no justification.
Therefore, in our opinion, there is no need to buy expensive neodymium magnets and use them for other purposes. You'll just be wasting your money.
Source: https://tze1.ru/articles/detail/neodimovye-magnity-chto-eto-takoe/
How are magnets made?
How are magnets made?
The unique properties of some substances have always surprised people with their unusualness. Particular attention was drawn to the ability of some metals and stones to repel or attract each other. Throughout all eras, this has aroused the interest of sages and the great surprise of ordinary people.
Starting from the 12th – 13th centuries, it began to be actively used in the production of compasses and other innovative inventions. Today you can see the prevalence and variety of magnets in all areas of our lives. Every time we come across another product made from a magnet, we often ask the question: “So how are magnets made?”
Types of magnets
There are several types of magnets:
- Constant;
- Temporary;
- Electromagnet;
The difference between the first two magnets lies in their degree of magnetization and the time they hold the field inside themselves. Depending on the composition, the magnetic field will be weaker or stronger and more resistant to external fields. An electromagnet is not a true magnet, it is just the effect of electricity that creates a magnetic field around a metal core.
Interesting fact : for the first time, research on this substance was carried out by our domestic scientist Peter Peregrin. In 1269, he published the “Book of the Magnet,” which described the unique properties of matter and its interaction with the outside world.
Neodymium
Iron, neodymium, boron, cobalt, samarium, alnico and ferrites are used to produce permanent and temporary magnets. They are crushed in several stages and together melted, baked or pressed to obtain a permanent or temporary magnetic field. Depending on the type of magnets and the required characteristics, the composition and proportions of the components change.
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This production makes it possible to obtain three types of magnets:
- Pressed;
- Cast;
- Sintered;
Making magnets
Electromagnet working principle
Electromagnets are made by winding wire around a metal core. By changing the dimensions of the core and the length of the wire, the power of the field, the amount of electricity consumed and the dimensions of the device change.
Component Selection
Permanent and temporary magnets are produced with different field strengths and resistance to environmental influences. Before production begins, the customer determines the composition and shape of future products depending on the place of application and the high cost of production. All components are selected to the nearest gram and sent to the first stage of production.
Smelting
Electric vacuum furnace
The operator loads all the components of the future magnet into an electric vacuum furnace. After checking the equipment and matching the amount of material, the furnace is closed.
Using a pump, all air is pumped out of the chamber and the melting process is started. Air is removed from the chamber in order to prevent oxidation of iron and possible loss of field power.
The molten mixture is poured into the mold on its own, and the operator waits for it to cool completely. The result is a briquette that already has magnetic properties.
Related materials:
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Grinding
The homogeneous alloy is crushed in special crushers in two stages. As a result of the primary crushing of the briquette, large particles the size of fine crushed stone are obtained. After secondary crushing, a powder with a particle size of several microns is formed. This is necessary in order to correctly set the magnetic fields at the next stage.
Pressing
The powder is loaded into a special apparatus, where, under the influence of a magnetic field and mechanical pressure, it is pressed into briquettes of the required sizes and shapes. When exposed to a magnetic field, the magnetized particles inside the powder are directed in one direction. As a result, the polarity of the future magnet is equalized. The finished briquettes are packed in sealed bags and the air is pumped out from the inside. This is necessary to prevent metal oxidation and loss of magnetic properties.
Sintering
The briquette is placed in a special oven, from which air is removed and all components are sintered into a single magnet under the influence of high temperature. The product gains high strength and increases the power of magnetic fields.
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Completion of production
Ready-made magnets
Magnets can be additionally cut, ground and coated with a protective layer. Finished products undergo quality control, are packaged and sent to the customer.
Interesting fact : the first mine for the production of magnetic ore was built on the magnesia hills in Asia Minor. Many tons of ore were mined from its depths, which were used to produce compasses and other unique tools.
The technology for producing magnets consists of mixing several components and obtaining a product that emits a magnetic field. Depending on the composition and proportions, in each individual case the process will be slightly different. Finished products will be used in various areas of our lives, from large electric motors to souvenirs for the refrigerator.
Source: https://kipmu.ru/kak-delayut-magnity/
Neodymium magnets - what are they and what are they for - Metals and their processing
One of the very fashionable types of treatment today is the use of magnets. Neodymium magnets, reviews of which are striking in their variety of emotional colors, are perhaps the most popular remedy, which is credited with the ability to heal a wide range of diseases. Which of the stories is true and which is speculation?
What is a neodymium magnet?
This is a rare earth element that has always been valued in medicine and technology for its very high resistance to demagnetization and the ability to strongly magnetize some materials.
Neodymium magnets have long been used to produce computer hard drives, metal detectors, and oil filters. Reviews from experts confirm their durability and ease of use. Power engineers use them to build generators.
In medicine, these magnets are used to operate machines that make MRI scans. By the way, the use of very large NMs in these devices helps:
- Achieve a uniform and uniform magnetic field without using electricity.
- Dispense with the cooling system necessary for the operation of the electromagnets.
Surgeons also use neodymium magnets. Reviews from these specialists emphasize that they make it possible to reliably clean severe wounds from lumps of iron, metal shavings, etc. Permanent magnets are used to operate tonometers and devices that make it possible to detect glaucoma in the early stages.
Compresses, rings, bandages, etc.
Recently, the range of applications of NMs has been expanding. Unique characteristics allow them to be used in microsurgery and cardiology, oncology, physiotherapy, dentistry, and orthopedics. Bandages, medicinal earrings and rings based on neodymium magnets have become popular.
Reviews from some doctors and patients say that magnetizing a sore spot can stop the growth of tumors, improve vision, and relieve pain. Based on NM, American specialists have created ultra-light pumps for blood vessels, which have already saved the lives of thousands of patients.
The tiny size of NM devices allows operations to be performed even on infants. Not very decent people also love neodymium magnets. Where is this miracle remedy used in everyday life? To stop home electricity meters, for example. But this, of course, is not its value. NM has a positive effect on biologically active points.
It normalizes blood pressure and blood circulation, helps activate the immune system, accelerates the treatment of inflammation, and serves as an excellent prevention of atherosclerosis.
How to properly use a neodymium magnet?
The price of this miracle product in online stores rarely exceeds 2-3 thousand rubles (size 70x50mm). In pharmacies you can find cheaper, although not as large and powerful specimens. A prescription is not required to purchase them, so some categories of patients try to treat themselves with them.
Is it dangerous! Without knowing the power of the magnet, you can cause very serious harm to yourself. Excitation of active points can cause an increase or critical drop in pressure, tachycardia and other abnormalities. Therefore, you can purchase magnets and use them only on the recommendation of doctors.
NM should not be used by pregnant women, people who have had a heart attack, or patients with poor blood clotting. The most effective treatment can be obtained in a physical therapy office.
Source: https://magnetline.ru/metally-i-splavy/neodimovye-magnity-chto-eto-i-dlya-chego.html
Where are neodymium magnets used?
Magnets have recently become increasingly popular, as evidenced by numerous requests from our customers, who, in turn, use them in everyday life, in industry, for the manufacture of various products (from souvenirs to electrical equipment).
Magnets come in different types: ordinary ferrite (the popularity of which is decreasing, since they are weaker than their analogues and demagnetize faster), samarium (used in industry) and neodymium . The latter are becoming increasingly famous and are in constant demand.
Often people call neodymium magnet as: super magnet, perpetual magnet, super magnet, powerful magnet, rare earth magnet, strong magnet, regular magnet, neodymium-iron-boron magnet, Nd-Fe-B magnet.
Some people mistakenly ask for niobium magnet, didymium magnet, neomagnet, neomidium magnet, nimidium magnet, needium magnet, neodyne magnet, nicodemium magnet, neodymium magnet, niodium magnet, niadium magnet, dionite magnet, edine magnet and even demonite magnet!
The correct name is still a neodymium magnet, since it contains the rare earth metal neodymium (Nd) , thanks to which the magnets get their unique properties: they are very powerful (even if they are small in size), are not subject to demagnetization (lose only 1% strength for a hundred years). In addition to neodymium, such magnets include iron (Fe) and boron (B).
Areas of use of neodymium magnets
A neodymium magnet can be used as a universal fastener for souvenirs, furniture, and curtains. Neodymium magnets are used as search magnets, as well as in electronics and even as toys (neocubes).
To ensure that neodymium magnets serve you for a long time, they are made with a special coating: it is either a nickel coating or a zinc coating. Nickel coating is most often used, but if you are going to use a magnet at temperatures above 100°C, or in an aggressive environment, we advise you to purchase a magnet with zinc coating.
The effect of magnets on health
Neodymium magnet is safe for health, and some claim that it is even useful, but so far there is no significant evidence for this. However, it is worth considering that people using a pacemaker should use strong neodymium magnets with caution.
Neodymium magnets can come in a variety of shapes. The most common: disk, block (parallelepiped), ring. The strength of a neodymium magnet depends on two factors: the amount of neodymium in the neodymium-iron-boron composition and the size of the magnet. The larger the magnet, the stronger it will be. The more neodymium it contains, the more pronounced its properties will be. Magnets are divided into classes based on the amount of neodymium; you can learn more about this division here.
Source: https://magnit96.com/blog/article/gde_ispol_zuyut_neodimovye_magnity/
Neodymium magnet. History of invention. Where are they used?
The strongest and most powerful permanent magnet currently available for sale is the neodymium magnet. Such magnets have the chemical formula Nd2Fe14B, and have an exceptional magnetic energy density reaching 512 kJ/m3.
If previously samarium-cobalt (SmCo) magnets were considered the most powerful commercially available, then, starting in 1986, they were gradually replaced by neodymium magnets, which were much more economical in production costs, although with a lower Curie temperature.
With the development of the electronics industry, from the 90s to the present, neodymium magnets have gained great popularity everywhere, and many are still surprised by their remarkable properties, because such a magnet can lift a load thousands of times greater than the weight of the magnet itself.
Neodymium magnet
It all started when in 1982 the Japanese company Sumitomo Special Metals, working together with the American General Motors on the problem of finding an alternative to expensive samarium-cobalt (SmCo) magnets, found a neodymium-iron-boron compound, which was patented by General Motors in 1985 In 1986, the Magnequench company was opened, specializing in the production of neodymium magnets and selling raw materials for their manufacture.
Magnequench later became part of Molycorp, USA, and Sumitomo became part of Hitachi Corporation, Japan, and Hitachi now holds more than 600 patents related to the production of neodymium magnets by sintering and licenses numerous facilities around the world.
In the end, China became the leader in the production of neodymium magnets, because this country controls a huge share of the world's rare earth ores.
China produces 50,000 tons of neodymium magnets every year. Meanwhile, one ton of the original ore contains about 700 kg of iron, and neodymium - a maximum of 450 grams.
Neodymium
For the manufacture of neodymium magnets, powder technology is used, which makes it possible to produce three types of magnets: pressed magnets, cast magnets, and sintered magnets.
Before making magnets, magnetic material is smelted; for this, the initial elements (iron, neodymium, boron) are fused in an induction furnace, then the resulting alloy is crushed, obtaining powder for further stages of the technological process, for working with the powder.
Characteristics of magnets
Depending on the microstructure of the starting elements, the magnetic properties of the final product may vary to some extent. Often the Nd2Fe14B compound is used directly. It is its structure that gives the maximum magnetocrystalline, uniaxial anisotropy. But more complex chemical reactions are also possible.
Sintered magnetoplasts
They are obtained by pressing neodymium-iron-boron powder, sintering it in an inert or vacuum environment, and then grinding it on a machine until the desired shape is obtained. During the pressing of the powder, it is acted upon by a magnetic field of the required intensity and direction, which sets the magnetization.
Cast magnets
They are obtained using polymers that are mixed with neodymium-iron-boron powder and then extruded into a mold, and here it is possible to obtain any shape, however, the energy of the product is limited to 5 MGE.
Pressed magnetoplasts
They are obtained as follows: the original neodymium-iron-boron powder is mixed with a polymer, then pressed into a shape, heated and magnetized. No additional processing is required, and the energy of pressed magnetoplasts is limited to 10 MGse.
Distinctive properties and technical characteristics
So, neodymium magnets have the following distinctive properties:
- Over 10 years, only 1% of magnetization is lost
- Any sizes and shapes available
- Low Curie temperature (see table above)
- High corrosion resistance
- Maximum remanence
- Maximum coercivity
- Maximum specific magnetic energy
Neodymium magnets are marked as follows, these are the so-called classes of neodymium magnets:
- N35-N52
- 33M-48M
- 30H-45H
- 30SH-42SH
- 30UH-35UH
- 28EH-35EH
Here the number denotes the magnetic energy expressed in MGse (MegaGauss-Oersted), and the letter (brand) is the permissible temperature range:
- N (Normal) – up to 80 degrees Celsius
- M (Medium) – up to 100 degrees Celsius
- H (High) – up to 120 degrees Celsius
- SH (Super High) – up to 150 degrees Celsius
- UH (Ultra High) – up to 180 degrees Celsius
- EH (Extra High) – up to 200 degrees Celsius
Usually, the seller is always ready to provide comprehensive information about the technical characteristics of the neodymium magnets he offers.
Scope of application of neodymium magnets
Neodymium magnets have almost completely replaced ferrite magnets in many applications, including industrial applications, as they are much stronger while being more compact.
Thus, neodymium magnets have found the following applications:
- in computer hard disk drives
- as part of erasing heads of inexpensive equipment
- in magnetic resonance imaging (MRI)
- in magnetic guitar pickups
- in electronic cigarettes
- in door locks
- in loudspeakers and headphones
- in magnetic bearings
- in NMR spectrometers
- in electric motors
- in cordless tools
- in servomotors
- in lifting and compressor engines
- in stepper motors
- in electric power steering
- on hybrid and electric vehicles
- in generators and turbines (direct drive turbines require 600 kg of magnets per megawatt of power, and 31% of this mass is neodymium)
Neodymium magnet toy
In addition, neodymium magnets with their unique magnetic properties have inspired the creators of toys and jewelry. Everyone knows the neocube magnetic kits and others; various construction sets, various decorative fasteners, etc.
Thus, neodymium magnets are capable of not only solving complex production problems, but also simple, convenient solutions.
Recently, powerful magnets have been actively promoted for use in illegal activities. The advertisement encourages you to buy magnets with which you can use electricity, heat and gas without accounting for the consumed resources with the corresponding meters. Unaccounted use of such resources is illegal, according to the Code of Administrative Offences.
See also on the topic:
Magnetic motor with permanent magnets. Minato engine.
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Source: https://powercoup.by/kak-eto-ustroeno/neodimovyiy-magnit
Application of neodymium magnets
The scope of application of neodymium magnets is incredibly wide, ranging from domestic use to medicine, industry, etc. It turns out that we come across such magnets very often, it’s just that no one really thinks about the fact that the basis of the things we are used to are the unique properties of this product.
Neodymium magnets in everyday life
Neodymium magnets are considered the best clamps and fasteners. Thanks to the power of the magnetic field, they are able to play the role of a vice. In everyday life, there is often a need to glue various materials or parts together. It is enough to place them between a pair of neodymium magnets, and extremely strong fixation will be ensured. It is also important that the force exerted by the magnet does not decrease over time, therefore the stability of the fixation is ensured.
Another advantage of neodymium magnets lies in their compact size, so they can be used for gluing parts and materials with complex configurations. Such magnets are also indispensable for fastening any metal objects. For example, you can place various devices on the walls of the kitchen, fixing them with magnets. By the way, with the help of powerful neodymium magnets, you can even hang a bicycle in the garage, not to mention tools.
The easiest way to find a lost metal object (a nail, keys or a needle) is to attach a magnet to some handy object and move it under furniture or along the floor for a while. During repairs, the location of the reinforcement in the walls can be determined in the same way.
Neodymium magnets can easily find objects made of any metal in soil and sand, so they can be used in searching for various products in nature. By the way, it was from this activity that many collectors of rarities began to get involved in treasure hunting.
Summer residents have the opportunity to use a magnet to retrieve objects that have fallen into a well, water tank or pond. For a similar purpose, neodymium magnets are used to lift metal objects from the bottom of rivers or lakes.
Today, every home has a computer, and the user has information recorded on a hard drive, CD, etc. If a hard drive or mobile storage device is broken, this does not mean that someone will not be able to read information from it. Therefore, before throwing away disks, treat them with a neodymium magnet, and the data will be guaranteed to be destroyed.
Another common application is the use of neodymium magnets for recreational purposes such as performing magic tricks, assembling models, and solving puzzles. In this area, the possibilities of such magnets are almost limitless.
You can attach them to two objects and perform a trick of attracting them to each other. There are few people who are not attracted to the popular neocube puzzle. This toy consists of many magnetic balls of the same size.
The stability of the design and the ability to assemble standard and original figures from the neocube are due to the magnetic field of the neodymium magnet.
Use of neodymium magnets by motorists
Car enthusiasts today use neodymium magnets to clean oil, in which metal particles accumulate due to friction of engine parts. A magnet can be used to “catch” such particles and concentrate them in places where they can be most easily removed. For example, you can attach a high-temperature magnet to the oil pan drain plug and clean it of stuck particles as needed.
A neodymium magnet is perfect for attaching various signs and signs to the roof, hood or trunk of a car, which will not move even during high-speed traffic or strong winds. Neodymium magnets can also be used to attach any devices in the cabin. In addition, magnets can magnetize tools (for example, a screwdriver) and restore the lost characteristics of other magnets.
Application in industry and other fields
The use of neodymium magnets in industry is due to the unique properties already described above.
In the production of units and parts, these products perform the function of a vice or clamps, but they also make it possible to sort metal objects and lift fairly heavy devices and products to a considerable height.
Such supermagnets are used in the manufacture of sensors and relays, in the production of electric generators, wind turbines and hydroelectric power stations, as well as diagnostic and medical equipment.
In the agriculture and food sectors, magnets are used to remove foreign metal objects from bags of cereals , grains and other products.
In workshops and workshops where large amounts of iron shavings are generated, neodymium magnets allow you to avoid injuries and easily solve the cleaning problem. For this purpose, a magnet is placed in a bag and brought to the place where metal shavings accumulate. The shavings stick to the magnet, and when the bag is turned inside out, they remain inside.
Powerful magnets are also used in the construction industry for fastening formwork, in the manufacture of cabinet furniture, jewelry and jewelry. Applications for neodymium magnets include, but are not limited to, modern medicine and the health industry.
Finally, magnetized water has a beneficial effect on the human body, and the force field generated by the magnet can normalize blood pressure and alleviate the symptoms of arthritis.
Application areas of magnets
— Advertising and souvenir products (magnets for folders, toys, jewelry, refrigerators, mounts for advertising posters, banners, posters, gift wrapping, etc.);
— Textile products (fasteners for bags, cosmetic bags, clothes, phone cases, etc.);
— Medicine (production of MRI, surgical equipment, diagnostic equipment);
— Oil and gas industry (sealed couplings and electric motors for submersible pumps, magnetic catchers and barriers, dewaxing machines, elements of diagnostic systems);
— Electronics (video equipment, audio equipment, personal computers, household appliances for various purposes);
— Nuclear production (magnetic centrifuges);
— Purification of liquids from metal impurities and scale formation (magnetic couplings and filters);
— Magnetic separation (separation of materials in glass, food, metallurgical, chemical and other industries, as well as in medicine and recycling);
— Automotive industry (microelectric motors, electromechanical converters, sensors, locking devices);
— Manufacturing of generators, engines, including hybrid ones;
— Production of lifting devices;
— Education and science.
Source: https://krasmagnit.ru/page/primenenie-neodimovyh-magnitov
Neodymium magnet: what does it mean and what is it made of, how to use
Neodymium magnet is the most powerful and permanent magnet, which contains rare earth neodymium, boron and iron. What is the complete definition of a magnet and its main advantages, what is its strength and what is its principle of operation? More on this later.
What it is
A neodymium magnet is a magnetic element that is composed of neodymium rare earth boron and iron material. It has a crystal structure, tetragonal shape and formula Nd2Fe14B.
Neodymium magnet is the most common type
It was first created by General Motors in 1982. It is the strongest permanent magnetic element, the power of which is several times greater than usual. Equipped with a large magnetic induction of 12,400 gauss.
Note! This is a brittle alloy with the formula NdFeB, as well as a hard nickel-plated protective layer and the corresponding class. It is very popular and comes in various forms.
Full material definition
Advantages
The most common neodymium magnet is one that has an iron oxide alloy, which has good heat resistance, high magnetic permeability and low cost. Equipped with color coding, high coercivity, powerful magnetic field to hold objects suspended, compact size, light weight, affordable and wide range of applications. Has a long service life.
If an ordinary magnet works for 10 years and can be demagnetized, then a neodymium magnet does not lose its properties after 100 years. Another advantage is the shape. This product has a horseshoe shape. It gives the device a long service life. As for the cost, these are expensive products, but the cost is justified by excellent performance and impeccable reliability.
Durability of work as one of the advantages
Force
It is worth pointing out that the strength contained in neodymium magnets is another advantage. She is tall and it is impossible to find a competitor to her. This is a record type of indicator, the increase of which is impossible. Power is generated during manufacturing. Magnetization occurs after the alloy is formed. Thanks to existing technologies, the alloy is magnetized in such a way that the magnet has incredibly high power and this figure reaches a record.
Note! Power is a relative philistine concept. The force is stable, but it is measured using instruments. In this case, the readings depend on the thickness of the surface and cleanliness. The separation angle can have some influence.
Strength as one of the advantages
Life time
The service life of the equipment, if used properly, is 30 years. Due to careless handling, the device may be damaged. The point is the lack of flexibility, as well as brittleness and cracking under heavy load. Falls, impacts, or reduced traction will reduce the life of the equipment. For this reason, it is necessary to avoid falls using parts that come into contact during movements.
Another extremely important point is the irreversible loss of magnetic properties due to heating. Therefore, grinding with cutting or drilling reduces the chain force and may ignite the alloy. If storage and operation are organized correctly, then magnetization is maintained for 10 years.
Long service life
Design
When answering the question of what a neodymium magnet is made of, we can point out that it is a rare earth element that contains an atom with lanthanide or actinide. The classic composition may still contain an additive.
It is used to increase strength with endurance and resistance to high temperatures. Boron is used in small quantities, iron is a binding element. Thanks to this composition, greater adhesion is obtained.
When connecting several ferrite rings, you can separate them with your hands. As for neodymium magnets, this cannot be done.
Composition of magnetic material
How are neodymium magnets magnetized?
The magnetization of neodymium magnets occurs through the interaction of bromine ions, iron and neodymium in a powerful magnetic field. Thanks to such actions, an element is obtained that has a high coercive force and high adhesion power. It also has an extremely long service life in everyday life.
Magnetization of neodymium materials
Principle of operation
A neodymium magnet works very simply. If two magnetic elements are connected and the poles coincide in direction, the magnetic force of the two fields will be enhanced. The result is an overall strong magnetic field. With the reverse arrangement of the magnetized elements, the magnetic field will be suppressed.
Principle of operation
How to use
Neodymium magnetic element is the strongest, exceeding analogues that are based on rare earth metal. In addition, neodymium is capable of maintaining a magnetized structure for a significantly long time. Such equipment can be used in various fields. For example, it is used in the manufacture of over-ear headphones with wind generators, motor wheels and scooters.
Note! Magnets are actively used in industrial, household, and medical fields. They are also used to carry out search work with a metal detector. They can often be found in plumbing fixtures or souvenirs.
Specific examples include the use of magnets in the development of medical devices, magnetic treatment of water, the creation of oil and technological filters, and the formation of actuators with highly sensitive sensors. In addition, they are needed to produce clothes with covers and shoes, and to create advertising, information and navigation materials.
Scope of application of the material
Overall, neodymium is the most powerful permanent magnetic material that has high resistance to demagnetization, attractive power, and a metallic appearance. It has a long service life and consists of boron, iron and a metal of the lanthanide group.
Source: https://rusenergetics.ru/polezno-znat/neodimovykh-magnitakh
What is a neodymium magnet: features and characteristics, scope of application
This is not the first year that there has been an active discussion on the Internet about neodymium magnets, their properties and use in everyday life. It is interesting to figure out how this magnet differs from a regular one and whether it actually corresponds to the qualities that are attributed to it in advertising.
What is a neodymium magnet and how does it differ from a regular one?
The main difference between neodymium alloy and other varieties is its power. A small piece containing boron, iron and neodymium molecules is capable of reliably holding a heavy load on its surface.
Unlike a simple ferrite composition, neodymium alloy has a special chemical lattice that cannot be obtained by combining any other elements. Scientists have proven that the attractive force of a permanent magnet is 18 times greater than the energy of its ferrite counterpart.
Production Features
In the production of neodymium magnets, a special technology is used, during which three substances are combined. Boron has the smallest specific gravity, and the maximum amount in the final substance is occupied by neodymium, a rare earth metal of the lanthanide group (element 60 in the periodic table). As for iron, its role in the alloy is reduced to a binding component.
In the manufacture of heavy-duty devices, a special technology is used. Unlike the production of simple products, the components are not melted, but sintered. This procedure makes the resulting substance brittle. It is in order to protect the finished product from chipping and rust that at the final stage the magnets are coated with a copper-nickel alloy.
Scope and methods of using devices in everyday life and beyond
Thanks to its special power, the invention of American scientists is increasingly displacing ferroalloys that are familiar to many from the market every day.
Heavy-duty lumps of complex composition are in demand in many areas, in particular, they are used for:
- production of computer equipment for household, industrial and medical purposes;
- making toys;
- cleaning industrial premises from metal shavings;
- production of household appliances.
The attractive force of the alloy allows you to search and lift metal objects from deep holes and hard-to-reach places. Thanks to the high power of the magnet, a small piece of combined metal can be easily moved to remote corners and at the same time collect the maximum number of small objects that could hardly be combined with ordinary ferrite.
In everyday life, neodymium magnets are used in the most unexpected places, for example, in glass washing devices and in household plots. In addition, powerful devices magnetize metal strips for attaching kitchen utensils, shelves and stands.
Car enthusiasts use “supermetal” to remove dents on car bodies.
In folk medicine, the super-powerful alloy is used to make medicinal jewelry that can normalize blood pressure and change a person’s aura.
Types and differences of such magnets
The main differences between neodymium magnets and ferrite products are:
- increased force of attraction;
- resistance to demagnetization;
- multipolarity.
In addition, unlike ferrite ones, heavy-duty lumps have a metallic sheen. Depending on the needs, products can take the form of plates (with or without holes), small cylinders or cones, cubes and balls of various sizes.
Advantages and disadvantages
The advantage of “supermetallic” lumps is their small size and high power. Rare earth metal products are shock resistant and last much longer than ferrite products.
As for the disadvantages, it should be said that the magnet, the size of a child’s palm, has a very noticeable weight. In addition, it is important to say that heavy duty alloy products have a high cost.
Also, the special coating layer should be protected, and that is why it is strictly forbidden to saw, drill or otherwise destroy the protective film yourself!
Thanks to the discovery of scientists, which occurred back in 1982, the life of mankind has changed for the better.
Source: https://VGrafike.ru/neodimovyj-magnit/
What is a magnet? Types and properties of magnets
Even in ancient times, people discovered the unique properties of certain stones - attracting metal. Nowadays, we often come across objects that have these qualities. What is a magnet? What is his strength? We will talk about this in this article.
Definition
What is a magnet? This is a material that has a certain degree of magnetization. This ability arises due to the fact that the molecules of a magnet have their own field and do not move chaotically, as in many other substances, but strictly in two directions. This mutual opposition has the properties of attraction and repulsion of metal objects.
If you try to connect magnets with the same poles, you may feel rejection. Opposite sides, in turn, will attract each other. This has to do with the direction in which magnetic field waves move. It is worth noting that no piece of magnet can be unipolar.
When it is broken, the molecules in each piece again form the north and south poles.
Types of permanent magnets
Ferrite magnets are the most famous and actively used in everyday life. This black material can be used as fasteners for various items, such as posters, wall boards used in the office or school. They do not lose their attractive properties at temperatures not lower than 250°C.
Alnico is a magnet consisting of an alloy of aluminum, nickel and cobalt. This gave it its name. Very resistant to high temperatures and can be used at 550°C. The material is lightweight, but completely loses its properties when exposed to a stronger magnetic field. Mainly used in the scientific industry.
Samarium magnetic alloys are high performance materials. The reliability of its properties allows the material to be used in military developments. It is resistant to aggressive environments, high temperatures, oxidation and corrosion.
What is a neodymium magnet? It is the most popular alloy of iron, boron and neodymium. It is also called a supermagnet, as it has a powerful magnetic field with high coercive force. By observing certain conditions during operation, a neodymium magnet can retain its properties for 100 years.
We found out what a magnet is. Next, we will consider the use of the most popular and popular alloys.
Use of neodymium magnets
It is worth taking a closer look at what a neodymium magnet is? This is a material that is capable of recording the consumption of water, electricity and gas in meters, and not only. This type of magnet belongs to permanent and rare earth materials. It is resistant to the magnetic fields of other alloys and is not subject to demagnetization.
Neodymium products are used in the medical and industrial industries. Also in domestic conditions they are used for attaching curtains, decorative elements, and souvenirs. They are used in search instruments and electronics.
To extend their service life, magnets of this type are coated with zinc or nickel. In the first case, spraying is more reliable, as it is resistant to aggressive agents and can withstand temperatures above 100°C. The strength of a magnet depends on its shape, size and the amount of neodymium included in the alloy.
Applications of Ferrite Magnets
Ferrites are considered the most popular permanent magnets. Thanks to strontium included in the composition, the material does not corrode. So what is a ferrite magnet? Where is it used? This alloy is quite fragile. That's why it is also called ceramic.
Ferrite magnets are used in automotive and industrial applications. It is used in various equipment and electrical appliances, as well as household installations, generators, and acoustic systems.
In automobile manufacturing, magnets are used in cooling systems, window lifters, and fans.
The purpose of ferrite is to protect equipment from external interference and prevent damage to the signal received via the cable. Thanks to this property, magnets are used in the production of navigators, monitors, printers and other equipment where it is important to obtain a clean signal or image.
Magnetotherapy
Physiotherapy with a magnet is often used. What it is? This procedure is called magnetic therapy and is carried out for therapeutic purposes. The effect of this method is to influence the patient's body using magnetic fields under low-frequency alternating or direct current. This treatment method helps get rid of many diseases, relieve pain, strengthen the immune system, and improve blood flow.
It is believed that diseases are caused by disturbances in the human magnetic field. Thanks to physiotherapy, the body returns to normal and the general condition improves.
From this article you learned what a magnet is, and also studied its properties and applications.
Source: https://FB.ru/article/345280/chto-takoe-magnit-vidyi-i-svoystva-magnitov
Permanent magnets
> Theory > Permanent magnets
There are two main types of magnets: permanent and electromagnets. You can determine what a permanent magnet is based on its main properties. A permanent magnet gets its name because its magnetism is always “on.” It generates its own magnetic field, unlike an electromagnet, which is made of wire wrapped around an iron core and requires current to flow to create a magnetic field.
History of the study of magnetic properties
Centuries ago, people discovered that some types of rocks have an original property: they are attracted to iron objects. Mention of magnetite is found in ancient historical chronicles: more than two thousand years ago in European and much earlier in East Asian. At first it was regarded as a curious object.
Later, magnetite was used for navigation, finding that it tends to occupy a certain position when given the freedom to rotate. Scientific research carried out by P. Peregrine in the 13th century showed that steel could acquire these characteristics after being rubbed with magnetite.
Magnetized objects had two poles: “north” and “south,” relative to the Earth’s magnetic field. As Peregrine discovered, isolating one of the poles was not possible by cutting a fragment of magnetite in two - each individual fragment ended up with its own pair of poles.
In accordance with today's concepts, the magnetic field of permanent magnets is the resulting orientation of electrons in a single direction. Only some types of materials interact with magnetic fields; a much smaller number of them are capable of maintaining a constant magnetic field.
Properties of permanent magnets
The main properties of permanent magnets and the field they create are:
- the existence of two poles;
- opposite poles attract, and like poles repel (like positive and negative charges);
- magnetic force imperceptibly spreads in space and passes through objects (paper, wood);
- An increase in MF intensity is observed near the poles.
Interaction of magnetic poles
Permanent magnets support the MP without external assistance. Depending on their magnetic properties, materials are divided into main types:
- ferromagnets – easily magnetized;
- paramagnetic materials – are magnetized with great difficulty;
- Diamagnets - tend to reflect external magnetic fields by magnetizing in the opposite direction.
Important! Soft magnetic materials such as steel conduct magnetism when attached to a magnet, but this stops when it is removed. Permanent magnets are made from hard magnetic materials.
How does a permanent magnet work?
His work deals with atomic structure. All ferromagnets create a natural, albeit weak, magnetic field, thanks to the electrons surrounding the nuclei of atoms. These groups of atoms are able to orient themselves in the same direction and are called magnetic domains. Each domain has two poles: north and south. When a ferromagnetic material is not magnetized, its regions are oriented in random directions, and their magnetic fields cancel each other out.
To create permanent magnets, ferromagnets are heated at very high temperatures and exposed to strong external magnetic fields.
This leads to the fact that individual magnetic domains inside the material begin to orient themselves in the direction of the external magnetic field until all domains are aligned, reaching the point of magnetic saturation.
The material is then cooled and the aligned domains are locked into position. Once the external MF is removed, hard magnetic materials will retain most of their domains, creating a permanent magnet.
Production of permanent magnets
Characteristics of permanent magnet
- Magnetic force is characterized by residual magnetic induction. Designated Br. This is the force that remains after the disappearance of the external MP. Measured in tests (T) or gauss (G);
- Coercivity or resistance to demagnetization - Ns. Measured in A/m.
Shows what the external MF intensity should be in order to demagnetize the material;
- Maximum energy – BHmax. Calculated by multiplying the remanent magnetic force Br and coercivity Hc. Measured in MGSE (megaussersted);
- Temperature coefficient of residual magnetic force – Тс of Br.
Characterizes the dependence of Br on the temperature value;
- Tmax – the highest temperature value, upon reaching which permanent magnets lose their properties with the possibility of reverse recovery;
- Tcur is the highest temperature value at which the magnetic material irreversibly loses its properties. This indicator is called the Curie temperature.
Generator with neodymium magnets
Individual magnet characteristics change depending on temperature. At different temperatures, different types of magnetic materials perform differently.
Important! All permanent magnets lose a percentage of their magnetism as the temperature rises, but at different rates depending on their type.
Alnico
These are permanent magnets consisting primarily of a combination of aluminum, nickel and cobalt, but may also include copper, iron and titanium. Due to the properties of alnico magnets, they can operate at the highest temperatures while retaining their magnetism, but they demagnetize more easily than ferrite or rare earth SmCo. They were the first mass-produced permanent magnets, replacing magnetized metals and expensive electromagnets.
Magnets in electric motors
Application:
- electric motors;
- heat treatment;
- bearings;
- aerospace vehicles;
- military equipment;
- high temperature loading and unloading equipment;
- microphones.
Ferrites
To make ferrite magnets, also known as ceramic, strontium carbonate and iron oxide are used in a ratio of 10/90. Both materials are abundant and economically available.
Due to their low production costs, resistance to heat (up to 250°C) and corrosion, ferrite magnets are one of the most popular magnets for everyday use. They have greater internal coercivity than alnico, but less magnetic strength than their neodymium counterparts.
Application:
- sound speakers;
- security systems;
- large plate magnets for removing iron contamination from process lines;
- electric motors and generators;
- medical instruments;
- lifting magnets;
- marine search magnets;
- devices based on the operation of eddy currents;
- switches and relays;
- brakes
Magnet in sound speaker
Rare Earth SmCo Magnets
Cobalt and samarium magnets operate over a wide temperature range, have high temperature coefficients and high corrosion resistance. This type retains magnetic properties even at temperatures below absolute zero, making them popular for use in cryogenic applications.
Application:
- turbo technology;
- pump couplings;
- wet environments;
- high temperature devices;
- miniature electric racing cars;
- radio-electronic devices for operation in critical conditions.
Neodymium magnets
The strongest existing magnets, consisting of an alloy of neodymium, iron and boron. Thanks to their enormous power, even miniature magnets are effective. This provides versatility of use.
Each person is constantly near one of the neodymium magnets. They are, for example, in a smartphone. The manufacture of electric motors, medical equipment, and radio electronics rely on ultra-strong neodymium magnets.
Due to their ultra-strength, enormous magnetic force and resistance to demagnetization, samples up to 1 mm are possible.
Neodymium magnets of different shapes
Application:
- hard disks;
- sound-reproducing devices – microphones, acoustic sensors, headphones, loudspeakers;
- prostheses;
- magnetically coupled pumps;
- door closers;
- engines and generators;
- locks on jewelry;
- MRI scanners;
- magnetic therapy;
- ABS sensors in cars;
- lifting equipment;
- magnetic separators;
- reed switches, etc.
Polymer magnets
Flexible magnets contain magnetic particles inside a polymer binder. Used for unique devices where installation of solid analogues is impossible.
Application:
- display advertising – quick fixation and quick removal at exhibitions and events;
- vehicle signs, educational school panels, company logos;
- toys, puzzles and games;
- masking surfaces for painting;
- calendars and magnetic bookmarks;
- window and door seals.
Most permanent magnets are brittle and should not be used as structural components. They are made in standard forms: rings, rods, disks, and individual: trapezoids, arcs, etc. Neodymium magnets, due to their high iron content, are susceptible to corrosion, so they are coated with nickel, stainless steel, Teflon, titanium, rubber and other materials.
Source: https://jelectro.ru/teoriya/postoyannye-magnity.html