How to make a permanent magnet from iron

How to magnetize metal - Metalist's Handbook

Judging by numerous reviews, when starting to carry out any work, home craftsmen often encounter one problem - magnetization of tools.

According to experts, this property of the metal in some cases significantly helps in work, since the tools become better.

For example, using a magnetized screwdriver it is much easier to tighten screws in the most difficult to reach places.

But many are also interested in the other side of the issue. How to demagnetize magnetized metal? This interest is due to the fact that in some cases magnetization is undesirable.

It is unlikely that you will be able to make high-quality markings with a caliper with metal shavings stuck to it. It is also inconvenient to use a magnetized cutter. These tools, as a result of exposure to a magnet, noticeably reduce their performance properties.

You will find information on how to demagnetize metal at home in this article.

Before you become interested in how to demagnetize metal, you should understand the nature of this phenomenon. According to experts, magnetization is carried out by paramagnets, diamagnets and ferromagnets.

Products based on alloys of iron, nickel and cobalt have their own magnetic field, which is higher than the external one. Tools become magnetized if they are used near electric motors or other emitters.

As a result, they will take away some of the magnetic properties.

About the use of magnetized tools

According to experts, some instruments are deliberately magnetized. These are mainly screwdrivers that are used when repairing mobile phones, computers and various household appliances. Such screwdrivers will become indispensable in situations where you need to tighten a screw, but there is no way to support it with your hands.

It is better not to subject watch instruments to the magnetization procedure, since this can stop their working mechanisms. It is not advisable to work with a magnetized drill or cutter, since small metal particles sticking to the working part of the tool will cause a lot of trouble for the master. Read on to learn how to demagnetize metal.

About the special device

Magnetometers are available especially for this purpose, through which a tool can be both given a magnetic charge and removed. For those who do not know how to demagnetize metal, experts recommend doing the following:

• First you need to determine what voltage the magnetic field is at. This is a very important aspect, since a mistake can lead to the opposite result.
• You also need to measure the voltage on the magnet. It must have the opposite sign.

After these steps, you should touch the magnetometer area to the instrument, as a result of which the latter will be demagnetized.

How to check?

According to experts, the entire work will take no more than 10 seconds. To check the functionality, the magnetized metal must be brought to the screw. This way the master will see at what level of magnetization the tool is. If the result is unsatisfactory, the procedure should be repeated and then checked again.

How to demagnetize metal using an electric motor?

First, the home craftsman should acquire a low-power asynchronous unit. In this case, the magnetization will be reduced by an alternating decaying magnetic field. Before you begin, you need to remove the rotor from the electric motor.

If you need to remove magnetization from tweezers or a drill, then you just need to insert these products into the stator for half a minute. If the stator windings are disconnected from the power supply, the rotation of the magnetic floor will begin to gradually fade away.

According to experts, the remaining magnetization of the tool will be so small that small metal shavings will no longer be able to stick to them.

Alternative option

Judging by numerous reviews, not everyone has the opportunity to get a low-power asynchronous electric motor.

Experts advise such craftsmen who do not know how to demagnetize metal at home to use a step-down transformer field. There must be an air gap inside its core.

You need to insert a magnetized tool into it for half a minute. It happens that the procedure does not produce results. In this case, it should be repeated.

Using a magnet

Often beginners are interested in how to demagnetize metal with a magnet. It is not difficult to cope with this work. The master should acquire an ordinary, but fairly large magnet, preferably round in shape.

Similar products are available in speakers. Next, a drill, tweezers or scissors are passed over the surface of the magnet. It can also be any other metal instrument.

The distance from the product to the magnet should be minimal.

About working with large batches of parts

There are times when it is necessary to remove magnetization from many metal products. This is possible through the desired temperature.

How to demagnetize metal by heating? According to experts, this will require heating the products to a certain state, which is also called the Curie point. Iron is heated to a temperature of 768 degrees. A ferromagnet will require a higher range.

Upon reaching the desired temperature threshold, spontaneous magnetized domains are formed.

The process goes as follows. First, one part is brought to the Curie point. Next you should cool it. It is important that it is not affected by external magnetic fields (the only exception is the Earth’s magnetic field).

Next, using a sensitive induction meter, the maximum magnetization is assessed. Next, in the control zone at a distance of no more than 2 cm from the part, the range of different values ​​​​obtained by the MF-23 or MF-23M indicator is measured.

Magnetic induction should be +/- 2 mT.

About a homemade device for demagnetization

Judging by numerous reviews, tunnel devices can be used for this purpose. The design of such a device includes a coil connected to the mains.

There is a hole inside the coil where the workpiece should be inserted. Demagnetization can be successfully performed using a homemade electromagnet.

It is not difficult to make it from some materials and available tools.

The operating principle is to control the current. Magnetization is carried out by constant voltage, and by alternating voltage - the opposite effect. The reels are made from old TVs.

It is enough to disassemble it and remove the demagnetization loop in the kinescope. Then it is folded at least twice. It all depends on what diameter the home craftsman needs.

It happens that one loop is not enough. In this case, it can be supplemented from another old TV. Further, the design is equipped with a fuse button, which will ensure uninterrupted operation.

A device designed for 220 Volts is suitable for permanent use, and 110 Volts are suitable for short-term connections. If the product is 12 V, then experts recommend using a transformer.

With such a homemade mechanism, you can successfully demagnetize even large parts.

Source: https://ssk2121.com/kak-namagnitit-metall/

How to make a strong magnet with your own hands at home? How to make a magnet at home

Sometimes people ask how to make a neodymium magnet with your own hands. Let's try to figure out how possible this is, and what the process of producing such products is all about.

So, the devices we sell consist of an alloy that is 70% iron and almost 30% boron. Only a fraction of a percent in its composition is made up of the rare earth metal neodymium, natural deposits of which are extremely rare in nature. Most of them are in China; they are found in only a few other countries, including Russia.

Before making neodymium magnets, manufacturers create molds for them from sand. Then the tray with the molds is doused with gas and subjected to heat treatment, due to which the sand hardens and retains the future outlines of the metal workpiece on its surface. Hot metal will later be placed in these forms, from which, in fact, the necessary products will be obtained.

Now let's directly look at how a neodymium magnet is made. Unlike ferromagnetic products, the metal here is not melted, but sintered from a powder mixture placed in an inert or vacuum environment.

Then the resulting magnetoplast is pressed while simultaneously exposing it to an electromagnetic field of a certain intensity. As you can see, even at the initial stage of production, it is noticeable that the question of how to make neodymium magnets at home sounds inappropriate.

The operations and equipment used are too complex. Creating such conditions at home is hardly possible.

After the workpieces are removed from the molds, they are subjected to mechanical processing - they are carefully polished, then they are fired to improve the coercive force of the products.

Finally, we come to the last steps, which will help to finally answer the question of how neodymium magnets are made. The sintered NdFeB alloy is again machine-finished using a special tool. During operation, a cooling lubricant is used to prevent overheating or ignition of the powder.

A protective coating is applied to the magnets. This is due, firstly, to the fact that sintered metals are quite fragile and need to be strengthened, and, secondly, the metal will be protected from corrosion processes and other environmental influences.

So manufacturers worry in advance about how to make a neodymium magnet stronger and more durable. The coating can be copper, nickel, zinc. In the last phase of the production process, magnetization is applied through a strong magnetic field.

Then they are sent to the warehouse, and from there to customers.

So, after we examined the production process in more or less detail, it became clear that we probably shouldn’t seriously ask the question “how to make a neodymium magnet at home.” After all, this requires not only certain knowledge, but many complex units.

How to make a magnet?

Every person has a magnet in their home; it can be used in the household or decorated and attached to the refrigerator so that it serves as an interior decoration. However, few people know that you can create it yourself at home. Below we will describe how to make a magnet with your own hands.

Making a magnet at home

There are several ways to make a magnet; Some of them are very simple, so anyone can do them. It just takes patience and a little skill. You will not need to collect certain metals, melt them and add special substances.

Method No. 1

You can make a magnet using a strong permanent magnet. You will only need to swipe the metal object in exactly one direction a few times. But such a magnet will retain its magnetic properties for a short period of time, so the procedure will have to be repeated from time to time.

Method No. 2

In order for a metal object to acquire magnetic properties, you need to pass an electromagnet across its surface. In this case, the object will retain its magnetic properties longer and will not need to be “magnetized” often. Read about making an electromagnet in our article.

Method No. 3

In order to make a more durable magnet, you will need to find a hardened steel bar and an inductor. However, the size of the piece of steel must completely fit inside the coil. To avoid a short circuit, it is better to include a fuse in the circuit.

To make a magnetized item last longer, it is recommended to find a bar made of steel, iron or alnico. The latter is quite difficult to find, but if you need a durable magnet, you can try to find it.

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Neodymium is a powerful permanent magnetic material. It is accessible to all people, so it can be used for different purposes. This is a rare earth magnet that contains an atom of lanthanides or actinides. Unlike a ceramic magnet, this design is quite strong and magnetized.

Application area of ​​neodymium magnet

Neodymium magnets are inexpensive designs that are often used for industrial and domestic purposes. Researchers and hobbyists can also use these materials to create their own projects and research. All hard drives that modern computers are equipped with have a small neodymium magnet. It guides the needle to correctly read the required information.

Neodymium magnets can be found in expensive acoustic systems, furniture fasteners, various accessories and many other things. The presented magnets can be used to create souvenirs.

There is only one drawback of this material - at high temperatures, a neodymium magnet can lose its original properties and energy.

It is for this reason that experts do not recommend using these structures in electronic and electrical devices where large amounts of thermal energy are generated.

Advantages of a neodymium magnet

The main advantage is incredible strength. Large magnets can support a weight of 10 kilograms. If you connect two magnets together and do not take into account the correct angle, you can get a skin injury, the attraction between them is so strong. Therefore, magnetic fasteners are often used in furniture production to create a reliable fastening element.

Often the presented designs can be found in an entertainment or educational project. A large number of people have already been able to estimate the service life of such magnets. Over the course of a hundred years, only 1% of its own magnetic energy is lost.

Ferrite magnets were most often designed in a horseshoe shape to complete the magnetic field line. Thus, manufacturers tried to increase the service life of this design.

Now it is best to buy and use neodymium magnets, which can be of any shape and will not lose their magnetic energy.

What are neodymium magnets made of?

During the production of this design, manufacturers use a unique alloy of neodymium, iron and boron. It has a high magnetizing force, so it rarely loses its properties. This permanent rare earth magnet can be found in generators, oil filters, and medical equipment. A 50x30 neodymium magnet is most often used in modern devices designed for magnetic resonance imaging.

Boron is the hardest element possible. It is inferior in its physical properties to diamonds, boron nitride and an alloy of silicon and carbon.

Iron is a metal that, when free, has a grayish or white tint. It is used in various admixtures to increase brittleness and hardness. It has pronounced magnetic properties. Neodymium is silvery-white in color, with a slight golden tint. It can oxidize quite easily in the air. Most often, this metal is used as an alloy component.

At home: method one

Source: https://valenteshop.ru/kak-sdelat-silnyi-magnit-svoimi-rukami-v-domashnih-usloviyah/

Making a magnet at home

Man first became acquainted with magnets in ancient times. However, very quickly this natural stone ceased to satisfy people's needs. It was then that the technology for making magnets was developed. Of course, a lot of time has passed since then.

Technology has changed significantly, and now it is possible to make a magnet at home. You don't need any special skills or knowledge to do this. It is enough to have all the necessary materials and tools at hand.

So, making a magnet looks like this.

Soft magnetic materials

All materials capable of magnetization can be divided into soft magnetic and hard magnetic. There is a significant difference between them. Thus, soft magnetic materials do not retain magnetic properties for long.

You can conduct an experiment: run iron bars over a strong magnet several times. As a result, the material will acquire the properties of attracting other metal objects. However, the manufacture of a magnet that constantly possesses these abilities is impossible in this case.

Hard magnetic materials

Such materials are obtained by magnetizing an ordinary piece of iron. In this case, the properties are preserved much longer. However, they completely disappear when the object hits a sufficiently hard surface. Also, the magnetic properties are destroyed if the material is heated to 60 degrees.

Making magnets with your own hands will not take much time and will not require any special expenses. For this you need:

• screwdriver;
• oiled paper;
• fuse;
• switch;
• copper wire;
• the strongest permanent magnet.

Method one

This method is considered the simplest. It is enough to hold a magnetized object several times in one direction against a permanent strong magnet. That's all.

However, it should be taken into account that magnets made using this method do not hold a magnetic field for long and very quickly lose their properties. Such products are suitable only for simple manipulations.

For example, such a magnet can help remove a needle that has fallen out of a crack or tighten bolts, but nothing more. Therefore, this method should not be seriously considered.

Method two

The production of permanent magnets can be carried out in another way. This requires a battery. With its help you can magnetize any suitable material. This is done quite simply and does not require special tools. An electromagnet gives a metal object magnetic properties.

Let's look at an example with a screwdriver. To begin with, the tool should be wrapped in an insulator, and then wound about 300 turns of wire. It is better to use the one that is used for the manufacture of transformers. After this, the wire must be connected to a battery or battery, preferably 5-12 volts. As a result of such manipulations, the electromagnetic field will magnetize the screwdriver.

Method three

Making a magnet may seem like a daunting task. Since the above methods do not guarantee that the properties will be maintained for a long time. A stronger magnet can be created using an inductor coil.

The metal blank must be small, since it will need to be placed inside the coil. After this, you should follow exactly the same procedure as indicated in the previous method. The only difference is that you need to make twice as many turns of wire, that is, 600.

Only in this case can a good magnet be obtained.

Method four

The manufacture of a magnet in this case involves the use of current from the electrical network. This method is quite dangerous, so all manipulations should be performed carefully and carefully. We will need a fuse, without which nothing will work. It must be connected in series with an inductor coil, inside of which there is a metal workpiece.

Of course, when such a design is connected to the network, the fuse will blow. However, during this short period of time, the metal workpiece will have time to charge, since in this case a fairly strong electromagnetic field is created. Here it is worth considering one nuance: the higher the current strength, the stronger the magnet will be. To wind the coil you should use only copper wire.

Finally

Making permanent magnets at home is a fairly simple process. However, you should be careful when using certain schemes.

Neodymium is considered the most powerful permanent magnet. You can make it at home, but this requires a piece of rare earth metal - neodymium. In addition, an alloy of boron and iron is used. Such a workpiece is magnetized in a magnetic field. It is worth noting that such a product has enormous power and loses only 1 percent of its properties over a hundred years.

Source: https://FB.ru/article/193286/izgotovlenie-magnita-v-domashnih-usloviyah

Powerful magnets

> Theory > Powerful magnets

Even in ancient China, attention was paid to the attractive properties of some metals. This physical phenomenon is called magnetism, and materials that have this ability are called magnets.

Now this property is actively used in radio electronics and industry, and especially powerful magnets are used, among other things, for lifting and transporting large volumes of metal. The properties of these materials are also used in everyday life - many people know magnetic cards and letters for teaching children.

What kind of magnets there are, where they are used, what neodymium is, this text will tell you about it.

Types of magnets

In the modern world, they are classified into three main categories based on the type of magnetic field they create:

• permanent, consisting of a natural material that has these physical properties, for example, neodymium;
• temporary, possessing these properties while in the field of action of a magnetic field;
• Electromagnets are coils of wire on a core that create an electromagnetic field when energy passes through the conductor.

In turn, the most common permanent magnets are divided into five main classes, according to their chemical composition:

• ferromagnets based on iron and its alloys with barium and strontium;
• neodymium magnets containing the rare earth metal neodymium in an alloy with iron and boron (Nd-Fe-B, NdFeB, NIB);
• samarium-cobalt alloys, which have magnetic characteristics comparable to neodymium, but at the same time a wider temperature range of application (SmCo);
• Alnico alloy, also known as UNDC, this alloy is characterized by high corrosion resistance and a high temperature limit;
• magnetoplasts, which are a mixture of a magnetic alloy with a binder, this allows you to create products of various shapes and sizes.

Ferrites

Alloys of magnetic metals are brittle and fairly cheap products with average qualities. It is usually an alloy of iron oxide with strontium and barium ferrites. The temperature range for stable operation of the magnet is not higher than 250-270°C. Specifications:

• coercive force – about 200 kA/m;
• residual induction – up to 0.4 Tesla;
• average service life is 20-30 years.

What are neodymium magnets

These are the most powerful of the permanent ones, but at the same time they are quite fragile and not resistant to corrosion; these alloys are based on the rare earth mineral - neodymium. This is the strongest permanent magnet.

Characteristics:

• coercive force – about 1000 kA/m;
• residual induction – up to 1.1 Tesla;
• average service life is up to 50 years.

Their use is limited only by the low limit of the temperature range; for the most heat-resistant brands of neodymium magnet it is 140°C, while less resistant ones are destroyed at temperatures above 80 degrees.

Samarium-cobalt alloys

Possessing high technical characteristics, but at the same time very expensive alloys.

Characteristics:

• coercive force – about 700 kA/m;
• residual induction – up to 0.8-1.0 Tesla;
• average service life is 15-20 years.

They are used for difficult working conditions: high temperatures, aggressive environments and heavy loads. Due to their relatively high cost, their use is somewhat limited.

Alnico

A powder alloy of cobalt (37-40%) with the addition of aluminum and nickel also has good performance characteristics, in addition to the ability to retain its magnetic properties at temperatures up to 550°C. Their technical characteristics are lower than those of ferromagnetic alloys and are:

• coercive force – about 50 kA/m;
• residual induction – up to 0.7 Tesla;
• average service life is 10-20 years.

But, despite this, it is this alloy that is most interesting for use in the scientific field. In addition, the addition of titanium and niobium to the alloy helps to increase the coercive force of the alloy to 145-150 kA/m.

Magnetic plastics

They are used mainly in everyday life for making magnetic cards, calendars and other small things; the characteristics of the magnetic field decrease slightly due to the lower concentration of the magnetic composition.

These are the main types of permanent magnets. The principle of operation and application of an electromagnet differs somewhat from such alloys.

Interesting. Neodymium magnets are used almost everywhere, including in design to create floating structures, and in culture for the same purposes.

Electromagnet and demagnetizer

If an electromagnet creates a field when passing through the turns of the winding of electricity, then the demagnetizer, on the contrary, removes the residual magnetic field. This effect can be used for various purposes.

For example, what can be done with a demagnetizer? Previously, the demagnetizer was used to demagnetize the playback heads of tape recorders, television picture tubes and perform other similar functions.

Today it is often used for somewhat illegal purposes, to demagnetize meters after using magnets on them. In addition, this device can and should be used to remove residual magnetic fields from instruments.

The demagnetizer usually consists of an ordinary coil, in other words, in terms of design, this device completely replicates an electromagnet. An alternating voltage is applied to the coil, after which the device from which we remove the residual field is removed from the demagnetizer's coverage area, after which it turns off

Important! Using a magnet to “twist” the meter is illegal and will result in a fine. Improper use of the demagnetizer can lead to complete demagnetization of the device and its failure.

Making your own magnet

To do this, it is enough to find a metal bar made of steel or other ferroalloy; you can use the composite core of the transformer, and then make a winding. Wind several turns of copper winding wire around the core. For safety, it is worth including a fuse in the circuit. How to make a powerful magnet? To do this, you need to increase the current strength in the winding; the higher it is, the greater the magnetic force of the device.

When the device is connected to the network and electricity is supplied to the winding, the device will attract metal, that is, in fact, it is a real electromagnet, albeit of a somewhat simplified design.

In the modern world, magnetic field energy is widely used. Both in industry, radio electronics and electrical engineering, and for domestic purposes. Dozens of different devices have been created to generate a magnetic field, and the natural properties of minerals are also used.

The most widely used permanent magnet is the neodymium magnet. Its use and widespread use is due to both its cost and excellent technical characteristics. Its disadvantages are: a tendency to corrosion and fear of high temperatures. For this reason, in difficult operating conditions, other types are used that do not have these limitations.

Magnetic field energy density

Source: https://jelectro.ru/teoriya/moshhnye-magnity.html

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?”

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:

How and from what is cement made?

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.

Related materials:

How and from what is sour cream made?

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/

3 different types of magnets and their uses

Magnets are materials that generate a field that attracts or repels certain other materials (such as iron and nickel) from a certain distance. This invisible field, known as the magnetic field, is responsible for the key properties of a magnet.

Ancient people have been using magnets since at least 500 BC, and the earliest known descriptions of such materials and their characteristics come from China, India and Greece about 25 centuries ago. However, artificial magnets were created back in the 1980s.

Obviously, not all magnets are made of the same substances, and therefore they can be divided into different classes depending on their composition and the source of magnetism. Below is a detailed list of the three main types of magnets, including their properties, strength, and industrial and non-industrial applications.

1. Permanent magnets

Once magnetized, permanent magnets can retain magnetism for a long time.
They are made from materials that can be magnetized and create their own permanent magnetic field. Typically permanent magnets are made from four different types of materials:

I) Ferrite magnets

Stack of ferrite magnets | Image credit: Wikimedia

Ferrite magnets (also called ceramic magnets) are electrically insulating. They are dark gray in color and look like pencil lead.

Ferrites are typically ferromagnetic ceramic compounds made by mixing large quantities of iron oxide with metallic elements such as manganese, barium, zinc and nickel. Some ferrites have a crystalline structure, such as strontium and barium ferrites.

They are quite popular due to their nature of being non-corrosive and hence used to extend the life cycle of many products. Ferrite magnets can be used in extremely hot environments (up to 300 degrees Celsius) and the cost of making such magnets is also low, especially if they are produced in large volumes.

They can be further classified as "hard", "semi-hard" or "soft" ferrites, depending on their magnetic properties.

Because hard ferrites are difficult to demagnetize, they have high coercivity. They are used to make magnets such as small electric motors and loudspeakers. Soft ferrites, on the other hand, have low coercivity and are used to make electronic inductors, transformers, and various microwave components.

II) Alnico magnets

Alnico 5 horseshoe magnet | This U-shape produces a powerful magnetic field between the poles, allowing the magnet to grip heavy ferromagnetic materials.

Alnico magnets are made up of aluminum (Al), nickel (Ni) and cobalt (Co), hence the name al-ni-co. These often include titanium and copper. Unlike ceramic magnets, they are electrically conductive and have high melting points.

To classify them (based on their magnetic properties and chemical composition), the Magnetic Materials Association assigned them numbers such as Alnico 3 or Alnico 7.

Alnikos was the strongest type of permanent magnet until the development of rare earth magnets in the 1970s. They are known to create high magnetic field strengths at their poles - up to 0.15 Tesla, which is 3,000 times stronger than the Earth's magnetic field.

Alnico alloys can maintain their magnetic properties at high operating temperatures, up to 800 degrees Celsius. In fact, they are the only magnets that exhibit magnetism when heated red hot.

These magnets are widely used in household and industrial applications: magnetron tubes, sensors, microphones, electric motors, loudspeakers, vacuum tubes, radars are a few examples.

III) Rare earth magnets

As the name suggests, rare earth magnets are made from alloys of rare earth elements. This is the strongest type of permanent magnet, developed in the 1970s. Their magnetic field can easily exceed 1 Tesla.

The two types of rare earth magnets are samarium cobalt and neodymium magnets. Both are vulnerable to corrosion and very brittle. Thus, they are coated with a certain layer(s) to protect them from chipping or breaking.

Samarium-cobalt magnets are composed of praseodymium, cerium, gadolinium, iron, copper and zirconium. They can retain their magnetic properties at high temperatures and are highly resistant to oxidation.

Due to their lower magnetic field strength and high production cost, they are used less frequently than other rare earth magnets. They are currently used in benchtop nuclear magnetic resonance spectrometers, high-end electric motors, turbomachinery, and many applications where performance must match temperature changes.

Neodymium magnets, on the other hand, are the most affordable and strongest type of rare earth magnet. They are a tetragonal crystal structure made from alloys of neodymium, boron and iron.

Due to their smaller size and light weight, they have replaced ferrite and alnico magnets in numerous applications in modern technology. For example, neodymium magnets are currently used in head drives for computer hard drives, electric motors for cordless tools, mechanical switches for electronic cigarettes, and mobile phone speakers.

IV) single-molecule magnets

A versatile intracellular protein called ferritin is considered a single-molecule magnet. It stores iron and releases it in a controlled manner.

Towards the end of the 20th century, scientists learned that some molecules [which are composed of paramagnetic metal ions] can exhibit magnetic properties at very low temperatures. In theory, they are capable of storing information at the level of magnetic domains and providing a much denser medium than traditional magnets.

Single-molecule magnets consist of clusters of manganese, nickel, iron, vanadium and cobalt. Some circuit systems, such as single-circuit magnets, have been found to retain magnetism for long periods of time at higher temperatures.

Researchers are currently studying monolayers of such magnets. One of the early compounds that was investigated as a single-molecule magnet is dodecanuclear manganese cage.

The potential applications of these magnets are enormous. These include quantum computing, data storage, information processing and biomedical applications such as MRI contrast agents.

2. Temporary magnets

Some objects can be easily magnetized even by a weak magnetic field. However, when the magnetic field is removed, they lose their magnetism.

Temporary magnets vary in composition: they can be any object that acts as a permanent magnet in the presence of a magnetic field. For example, soft magnetic materials such as nickel and iron will not attract paper clips once the external magnetic field is removed.

When a permanent magnet is brought near a group of steel nails, the nails are attached to each other and then to the permanent magnet. In this case, each nail becomes a temporary magnet, and when the permanent magnet is removed, they no longer attach to each other.

Temporary magnets are mainly used to make temporary electromagnets, the strength of which can be varied according to the requirements. They are also used to separate materials made from metal in scrap yards and give new impetus to modern technology - from high-speed trains to high-tech space.

3. Electromagnet

Electromagnet attracting iron filings

The electromagnet was invented by British scientist William Sturgeon in 1824. It was then systematically refined and popularized by the American scientist Joseph Henry in the early 1830s.

Electromagnets are tightly wound coils of wire that act as magnets when electrical current passes through them. It can also be classified as a temporary magnet because the magnetic field disappears as soon as the current is switched off.

The polarity and strength of the magnetic field created by an electromagnet can be adjusted by changing the direction and magnitude of the current flowing through the wire. This is the main advantage of electromagnets over permanent magnets.

To enhance the magnetic field, the coil is usually wound around a core of "soft" ferromagnetic material such as mild steel. A wire coiled into one or more loops is called a solenoid.

These types of magnets are widely used in electrical and electromechanical devices including hard drives, loudspeakers, hard drives, transformers, electric bells, MRI machines, particle accelerators and various scientific instruments.

Electromagnets are also used in industry to grip and move heavy objects such as scrap metal and steel.

Source: https://new-science.ru/3-raznyh-tipa-magnitov-i-ih-primenenie/

How to magnetize metal at home

Judging by numerous reviews, when starting to carry out any work, home craftsmen often encounter one problem - magnetization of tools. According to experts, this property of the metal in some cases significantly helps in work, since the tools become better. For example, using a magnetized screwdriver it is much easier to tighten screws in the most difficult to reach places.

But many are also interested in the other side of the issue. How to demagnetize magnetized metal? This interest is due to the fact that in some cases magnetization is undesirable.

It is unlikely that you will be able to make high-quality markings with a caliper with metal shavings stuck to it. It is also inconvenient to use a magnetized cutter. These tools, as a result of exposure to a magnet, noticeably reduce their performance properties.

You will find information on how to demagnetize metal at home in this article.

What is the cause of magnetization?

Before you become interested in how to demagnetize metal, you should understand the nature of this phenomenon. According to experts, magnetization is carried out by paramagnets, diamagnets and ferromagnets. Products based on alloys of iron, nickel and cobalt have their own magnetic field, which is higher than the external one. Tools become magnetized if they are used near electric motors or other emitters. As a result, they will take away some of the magnetic properties.

How to magnetize a magnet at home - Metals, equipment, instructions

Using strong neodymium magnets, you can easily remagnetize your old magnets so they become magnets once again.

If you have old magnets that stop attracting and lose their magnetic properties, don't despair and don't throw them away before you try to recharge them.

Neodymium magnets are part of the rare earth group of magnets and are called NdFeB magnets (NFB) because of their composition: Nd = Neodymium, Fe = Iron and B = Boron.

• 1 Understand why magnets lose their magnetization. Over time, older types of magnets (not neodymium magnets) lose their magnetization if they: - were stored incorrectly (without a ferromagnetic armature that completes the magnetic circuit), - were dropped, - were stored with other magnets
• 2 Understand how magnets work. Good working magnets have two poles: a North Pole and a South Pole. They are located at the ends of the magnet and the magnet is strongest there. The magnet is weakest in the very middle. Fields tend towards their opposites. Remember that singly charged magnetic poles repel, and opposite magnetic poles attract.
• 3 Santa and his magnets live at the North Pole. Identify the poles of a strong magnet. You will need to identify the North Pole of a strong magnet. You can do this in the following ways: - use a magnet with the north and south poles marked (the easiest method!) - stack an even number of magnets together and hang them by a string tied in the middle, allowing the stack of magnets to spin freely. The North Pole will point north. (This is contrary to the rule about poles being attracted to their opposites, but they were named after the location of north and south, after which the names of the poles were shortened to north and south.) - use a compass and the arrow that usually points north will point to the South Pole of the magnet
• 4 Remagnetize the old magnet. Take your old magnet and a strong magnetized magnet with the north and south poles marked. One side or end will be north and the other side or end will be south. Pat or rub a strong neodymium magnet with its North Pole along one side or end of the old magnet. Then rub the neodymium magnet along the other side or end of the old magnet, with its South Pole. This should remagnetize or recharge your magnet.

• Because of its strength, a neodymium magnet is required to do the same job as older, much smaller magnets.
• Recharge or remagnetize old magnets with kids for a quick science lesson.
• Keep all magnets away from your computer.

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• 3 How to determine the phases of the moon
• 4 How to Remagnetize Old Magnets Using Neodymium Magnets
• 5 How to make a rain gauge from a plastic bottle

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How to make a magnet?

Every person has a magnet in their home; it can be used in the household or decorated and attached to the refrigerator so that it serves as an interior decoration. However, few people know that you can create it yourself at home. Below we will describe how to make a magnet with your own hands.

There are several ways to make a magnet; Some of them are very simple, so anyone can do them. It just takes patience and a little skill. You will not need to collect certain metals, melt them and add special substances.

You can make a magnet using a strong permanent magnet. You will only need to swipe the metal object in exactly one direction a few times. But such a magnet will retain its magnetic properties for a short period of time, so the procedure will have to be repeated from time to time.

In order for a metal object to acquire magnetic properties, you need to pass an electromagnet across its surface. In this case, the object will retain its magnetic properties longer and will not need to be “magnetized” often. Read about making an electromagnet in our article How to make an electromagnet.

In order to make a more durable magnet, you will need to find a hardened steel bar and an inductor. However, the size of the piece of steel must completely fit inside the coil. To avoid a short circuit, it is better to include a fuse in the circuit.

To make a magnetized item last longer, it is recommended to find a bar made of steel, iron or alnico. The latter is quite difficult to find, but if you need a durable magnet, you can try to find it.

How to magnetize a magnet yourself, is this possible if the magnet was hanging on the gate and lost power?

The old magnet can be recharged with a new strong neodymium magnet.

If the magnet is not completely discharged and there are no pole markings on it, first try to determine its north-south poles.

When you have determined it, rub a strong magnet against a weak one: the northern end against the northern one, and the southern end against the southern one. You need to rub in one direction - from the center to the edge.

If you couldn’t determine the poles of the old magnet, it’s okay, it means it’s completely exhausted and will still recharge after the neodymium magnet.

Once upon a time, in a young radio technician's group, we magnetized screwdrivers so that they would hold small screws. To do this, they wrapped insulating paper around the screwdriver shaft and wrapped it with a wire from a disassembled transformer, then they briefly connected the battery and the screwdriver became magnetic.

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You can use the same method. You just need to wind a LOT of turns of insulated wire onto the magnet, sorry I don’t know how many exactly - you need to experiment, but at least half a thousand turns that’s for sure.

In order for the magnet to become strong, a decent amount of current will have to pass through.

To do this, take an electrical plug with a cable and screw it to the wires on a magnet, connect only one wire through a 1-1.5A fuse, and insert the plug into the socket.

The fuse will quickly blow and the current will not have time to change direction, it will only make a half-sine wave, which means the magnetic field will be constant, so it will magnetize the old magnet.

You can magnetize an old demagnetized magnet using a powerful (strong) neodymium magnet.

It is enough to know a few important points regarding magnets in general:

Magnets have a “North Pole” and a “South Pole” located at the ends of the magnets.

They are designated by letter and color, “N” is the north pole, “S” is the south pole.

Single-charge poles repel, differently charged (opposite, that is) poles attract.

Decide on the poles of the neodymium magnet and the poles of the old (not working) magnet.

That’s all the preparation (theoretical), and then the process of magnetization itself, simply with three powerful magnets along the edges of the demagnetized one (north-north, south-south), first along one side, then along the other.

As a rule, these actions are quite enough for the magnet to “recharge” and work as before.

There are other, more complex ways to magnetize old magnets.

In order to avoid the problem of magnets demagnetizing in the future, they must be stored correctly; there are a number of rules.

The answer is clear, of course it is possible, but this requires a source of a very powerful magnetic field.

I think it’s unlikely that you will find a magnetizer with coils with a power of about 10 kilowatts in your stash, but finding a large and powerful neodymium magnet is quite possible.

The magnets need to be folded with their sides attracted to each other and the centers aligned, fixed in this position with non-magnetic materials, since when magnetized they will move relative to each other and left like that for about 2 hours, this will be enough.

In general, nothing is impossible, the question is whether it is advisable to damage another magnet in order to recharge the demagnetized one.

Source: https://spb-metalloobrabotka.com/kak-namagnitit-magnit-v-domashnih-usloviyah/

How magnets are made for different applications

There are many interesting substances in the world that surprise people with their unique properties and unusualness. And since ancient times, the best minds on the planet could not understand how individual stones and metals could attract or repel each other. Now science has stepped far forward, and free access to any information allows you to understand how magnets are made in a couple of minutes.

A little history

Things that are ordinary for a modern person can have a very complex history. And the magnet is no exception. The special field that is created by different materials caused not only delight, but also surprise among the sages of past eras. At the same time, people have encountered this phenomenon for a very long time. But the active development of the science of the magnetic field began relatively recently, and it was used for economic purposes literally a couple of decades ago.

There are a lot of historical facts that highlight the centuries-old history of a specific field with unique attractive or repulsive properties. The first reliable mention goes back to Ancient Greece, where the region of Magnesia once existed. It was in this geographical region that deposits of the substance that formed such a field were found. Soon the rock was called “stone from Magnisia”.

In addition to the real physical ability to attract iron objects, such stones were also endowed with mystical meaning. They were considered a gift from the gods, capable of scaring away evil spirits, healing fatal diseases and bringing good luck to the home. However, people soon managed to invent the first prototype of a compass, giving the object the shape of a needle that always points north.

A large number of references to the miracle field are present in Chinese chronicles. There, miraculous properties were attributed to the stones, and legends were also dedicated to them. For example, there is a legend about a mystical gate through which people with swords could not pass. Leading modern scientists are of the opinion that these gates were created from rock that attracts metal objects.

Natural and artificial origin

In medieval times and until the end of the 18th century, researchers actively studied the characteristics of rock with a magnetic field. In fact, then people did not know about the existence of other substances that generate this field.

But at the beginning of the 18th century, the famous scientist Arago, and soon Ampere and Seturgeon, managed to invent an object with a magnetic field of artificial origin. It was formed as a result of the supply of electric current, which was a real technological breakthrough.

Soon the technology began to be improved in every possible way, turning metal products into powerful variable magnets.

How stones are mined: features of the procedure and its regulation by law

Today magnets are classified into the following types:

1. Natural or natural.
2. Artificial.

Representatives of the first group are deposits of a special rock. The largest natural magnet ever found weighs 13 kilograms and guarantees an adhesive force of up to 40 kg.

As for artificial magnets, they are iron products that create a field when an electric current is applied to the stitching with the core. However, today there is a special type of magnets that is created by man using advanced technologies.

Main types

In addition, the listed types of magnets may differ in the principle of their operation. So, today the following types are distinguished:

1. Constant.
2. Temporary.
3. Electromagnet.

The first two varieties are characterized by different degrees of magnetization and time of retention of the field within themselves. Its intensity and resistance to external influences is determined by the composition of the material. The latter type does not belong to the group of true magnets, because it works due to the effect of electricity created by the magnetic field around the core.

Permanent and temporary magnets are created from different raw materials. in its quality :

1. Neodymium.
2. Bor.
3. Cobalt.
4. Alnico.
5. Iron.
6. Ferrites.

The materials are carefully crushed and then melted and kept in an oven at high temperatures until they acquire the desired properties. Depending on the type and required characteristics, the appropriate composition and proportions of components are set at the production stage.

Using this technology, the following types of magnets can be obtained:

1. Pressed.
2. Cast.
3. Sintered.

Production process

To create an electromagnet, you need to place a wire winding around a metal core. By changing the dimensions of the core and the length of the wire, you can change the intensity of the field, the amount of energy consumed, as well as the dimensions of the product.

Permanent and temporary magnets can have different field strengths and demonstrate different resistance to environmental influences. Before starting the manufacturing process, the customer needs to determine the composition and shape of the future product, taking into account the scope of application and the cost of services. The necessary components are selected with maximum precision, after which the first production stage begins - smelting.

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During smelting, a specialist immerses all components of the future object into an electric vacuum furnace. After checking the devices for operability, and the composition of the material for compliance with the proportions, the tank can be hermetically sealed.

Then, using powerful pumping equipment, air is pumped out of the chamber, which is necessary to prevent oxidation processes and possible loss of field power. The molten mixture is then poured into the mold, and the operator waits for it to cool completely.

In this way, a special briquette is created that has certain magnetic properties.

At the next stage, the resulting homogeneous mass is crushed using special crushers. Secondary crushing leads to the formation of a powdery consistency with dimensions of several microns. This requirement is necessary for the correct installation of magnetic fields.

Next, the powdery mass is placed in a special device, where it is exposed to mechanical pressure and a magnetic field. Thus, it is pressed into briquettes with the desired size and shape.

When a magnetic field is applied, the magnetized particles receive a one-way direction, which allows the polarity of the future magnet to be equalized. The finished product is packaged in a sealed bag, after which the air is pumped out of it.

Such measures are necessary to prevent oxidation processes and deprivation of magnetic properties.

Then the briquette ends up in a special oven, which is also pre-cleaned of air, and they begin to sinter into a single magnet using high-temperature effects. Ultimately, the product becomes very durable, and the intensity of the magnetic field increases.

Types of refrigerator magnets

There are different applications for magnets, but the most popular is the manufacture of refrigerator magnets. This accessory is in particular demand, because it allows you to increase the recognition of the company or serves as a souvenir from another city, country, or interesting place.

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Magnets available on the market come in a wide variety of shapes and materials. They are created on the basis of vinyl with magnetic properties, ceramic materials, glass, polymer blanks, plastic, gypsum, etc.

If we highlight the most famous varieties that are in demand among a wide audience of buyers, then they should be included .

1. Flat models. They are created on the basis of magnetic vinyl, on top of which there is a picture with or without a laminated coating. They are famous for their special softness, flexibility and resistance to any impact. This type is ideal for creating promotional products.
2. Sunsets. They have a beautiful design and look like an icon. They can have either a rectangular or rounded shape.
3. Resin. They are created on the basis of essential resins and are particularly attractive. Soft and hard magnets are sold on the market, which are an excellent addition to a successful business.

Do-it-yourself subtleties

Having understood the principle of the magnetic field and the basic technological processes for producing magnets, many enthusiasts may want to create such a product at home. Naturally, it will not be possible to create a super-strong magnet from improvised materials, but it is quite possible to make an interesting homemade product that retains the properties of attracting and repelling individual objects. And one such homemade product is a refrigerator magnet.

The simplest and most primitive way to make such accessories is to use magnetic vinyl. It can be purchased at the appropriate store, paying attention to the model with a thickness of 0.4 mm, as well as a glossy or matte finish for an inkjet printer. Next you need to apply a suitable picture to the source material by printing it on a printer. Despite its simplicity, the method has many disadvantages:

1. Buying magnetic vinyl is not a cheap pleasure. At the same time, the small thickness of the product significantly reduces the strength of attraction. Therefore, such magnets are suitable only for private use, because it is unlikely that anyone will want to buy them.
2. The quality of the final product is low, and the product itself cannot boast of a long service life. And the cause of such shortcomings may not be the vinyl magnet itself, but the presence of a color print from the printer.

The second production option involves printing photographs or graphic images on high-quality photo paper, followed by gluing a vinyl magnet with an adhesive base. The picture is additionally laminated and then fixed to a magnetic surface.

Both methods are simple enough to implement at home and do not require specific skills. All you may need for the upcoming work is:

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1. Personal computer or laptop with a pre-installed graphics editor. It is advisable to use Photoshop.
2. Inkjet printer that supports color printing functions.

   It is advisable to give preference to expensive models, since they work much faster and better.

3. Cutting device.

   Being a soft, rubber-like material, vinyl can be easily cut with regular scissors, but to ensure straight edges and proper cutting, it is better to invest in professional cutters.

Interesting Facts

Despite their physical properties, objects that create a magnetic field have always been considered something mysterious, as if from another planet. It’s no wonder why so many legends and interesting facts were born around them. The most popular historical references include:

1. History claims that Queen Cleopatra, considered the most beautiful woman of all time, owned magnetic jewelry in the belief that it could delay aging.
2. Most magnets are made from iron and steel, but the most powerful models are made from nickel alloys, copper, aluminum and cobalt.
3. When heated, an object loses its magnetic properties.
4. Household monitors and cathode ray tube televisions are equipped with an electromagnet to control electrons and send pictures to the screen.
5. It is difficult to imagine modern medicine without the use of different types of magnets. With their help, doctors effectively fight the most complex diseases.
6. Planet Earth is the largest magnet that causes compass needles to move in the desired direction.

In general, the characteristics of the magnetic field and the objects that create it are a truly fascinating topic. And despite the development of science and technology, many properties and facts about such substances are still poorly understood.

Source: https://rocca.ru/nauka-i-obrazovanie/kak-delayut-magnity