Use of magnets. Magnets and magnetic properties of matter

In electrical engineering, ferromagnets play a significant role. Different requirements may be presented to ferrimagnetic materials depending on their purpose.

Permanent magnets

Special magnetic materials with specified properties were created. So, in order to get a permanent magnet, it is necessary to find a ferromagnet whose hysteresis loop would be as wide as possible. What would mean, with a zero external magnetic field (after its shutdown), residual magnetization was as large as possible. Great, also the coercive force of such magnets. For such a substance, the boundaries of domains must remain unchanged. Such material was created. Its name $ Alnico V $ is a alloy, it has a composition: $ 51 \\% FE, 8 \\% Al, 14 \\% Ni, 24 \\% CO, 3 \\% Cu $. The movement of domain walls in this alloy is extremely difficult. In the process of solidification, Alnico V forms the "second phase", which has a grain composition. The substance is cooled in an external magnetic field, while grains grow in the desired orientation. In addition, the material is still being machined in such a way that its crystals are built in the form of oblong grains in the direction of the lines of preferential magnetization. The hysteresis loop for this ferromagnet is obtained 500 times wider than the hysteresis loop of soft iron. $ Alnico $ is a thermostable magnet, has a high corrosion and radiation resistance. Residual magnetization of the order of $ b_r \\ SIM 1.1-1.5 \\ T., $ coercive force $ H_k \u003d 0.5-1.9 \\ K $ (Kila Ersted). Maximum operating temperature up to $ 450 ^ ° C $. Now attempts are made to make nanostructured alloys. Used B. acoustic systems, Studio microphones, pickups, electric motors, relays, sensors.

Sintered rare earth magnets based on SMCO. Do not require protective coating, have high operating temperatures and high coercive force, that is, resistant to demagnetization. But rather fragile and very expensive. Residual magnetization of order $ B_R \\ SIM 0.8- \\ 1,1ТL, $ coercive force $ H_k \u003d 8-10 \\ KE. \\ $ Used in spacecraft, mobile telephony, computer equipment, aircraft manufacturing, medical equipment, micro electromechanical instruments.

Neodymium magnets, ND-FE-B alloys. Working temperatures low $ -60-220 ^ OC $. Rather fragile. If overheats require magnetization. Sounded corrosion. Easily processed mechanically, flexible. Sintered neodymium magnets have the greatest residual magnetization of the order of $ b_r \\ SIM 1- \\ 1,4TL $, the coercive force $ H_k \u003d 12 \\ KE. \\ $ Are used in computer engineering, engines, sensors.

Magnets can lose magnetization in mechanical vibrations, deformations, temperature drops. Complete demagnetization occurs at temperatures above the Curie point, in strong magnetic fields, if the ferromagnet is located in a decaying alternating magnetic field or a constant external field has the opposite direction to the inner field. Iron magnets are demagned at room conditions for many decades. Many artificially created magnets are growing rapidly.

Permanent magnets also apply:

• As clamps, fastening, fixing objects.
• To search for iron objects by sensing methods, cleaning metal garbage.

Use "soft" ferromagnets

Ferromagnetics are used in the manufacture of transformers and engines. But in this case, the ferromagnet must have other properties than suitable for permanent magnets. Material must be "soft" in magnetic terms. Its magnetization should easily change when changing an external magnetic field. Requirements for ferromagnetics in this case are: high magnetic permeability and weak hysteresis. In this case, clean substances are used without impurities with a minimum number of domains, the walls of the domains should easily move. The anisotropy of crystals are trying to minimize. In this case, if the grains of the substance are under an irregular angle to the field, the magnetic is still well magnetized. So, the alloy of iron and nickel (about 80 \\% Ni and 20 \\% Fe) were doped with chromium, copper or silicon, and it turns out a very "soft" alloy, which is easily magnetized. Such substances are called Permallo.

Good magnetic properties Permalloe, which contains 78.5 nickels obtained with two-step thermal heat treatment. At the first stage it is heated to $ 900-950 ^ ° C $ and withstand around an hour, then cooled at low speed. At the second stage, heating takes up to $ 600 ^ ° C $ and cooling at room temperature at a rate of 1500 $ \\ FRAC (hail) $.

They are used in high-quality transformers, but are not suitable for permanent magnets. Permalloe do not tolerate deformations, their properties change significantly.

Alloys with maximum magnetic permeability are used for cores of small-sized transformers, relays, magnetic screens, magnetic amplifiers, relays. Alloys with increased resistivity are used for cores of pulse transformers, high-frequency equipment.

When calculating all sorts of devices alternating currentthat contain ferromagnets, always carry out the calculation of the thermal effect in the hysteresis. Availability of this phenomenon in iron cores of transformers or rotating generators direct current He leads to the cost of the energy of the energy on the heat of hysteresis, which reduces the efficiency of the devices. It means that for such devices, you should select special varieties of ferromagnets, hysteresis loop area for which, minimal.

Studies have shown that some alloys of nonferromagnetic metals in a certain ratio of the component have strong ferromagnetic properties. For example, Manganese - Bismuth, Chrome - Tellur, etc.

Ferrites

In the event that the magnitude of the magnetization of the sublattice is different, then non-composed antiferromagnetism occurs. The body can have a significant magnetic moment. Such substances are called ferrimagnets. In their magnetic properties, they are similar to ferromagnets. If ferrimagnetics have semiconductor properties, they are called ferrithic semiconductors, which have a large electrical resistivity (about $ (10) ^ 2- (10) ^ 6Ω \\ Cdot cm $). The magnetization of saturation in ferrimagnets is less than that of ferromagnets. They are useful only with weak fields. Ferritis - ferromagnetic insulators. Vortex currents that are created in them in the fields with high frequency Very small, it allows the use of ferrites in microwave. Micropolis penetrate inside ferrite, whereas in ferromagnets it is not possible due to the vortex currents.

These substances are also used in radio engineering at high frequencies, where in ferromagnets due to their large conductivity there are large losses for vortex currents.

Example 1.

Task: Which of ferromagnetic materials, in Figure 1 is most suitable for electromagnets with rapid adjustment of the lifting force? For permanent magnet?

For a permanent magnet, a ferromagnet with a wide hysteresis loop is more suitable, which corresponds to a large coercive force, allowing the substance to demagnetize at a lesser speed and high residual magnetization. So, the ferromagnet with number 1 is more suitable for a permanent magnet.

For an electromagnet with rapid adjustment, a ferromagnet is needed, which has a narrow hysteresis loop, less coercive force and residual magnetization, therefore, for these purposes it is more convenient for the ferromagnet number 2.

Example 2.

Task: Is it possible to carry the hot steel pipes with an electromagnetic crane?

Obviously, it is not worth it, since ferromagnetic properties at temperatures above the Curie point ferromagnetic are lost, and it will become a paramagnet with a very small magnetic permeability and its magnetic properties will be insufficient, for use as a means of transporting pipes.

At the very beginning of work, it will be useful to give daily payments.

If, in some place, on moving bodies, possessing a charge, the force acts that does not act on fixed or devoid of body, they say that in this place is present a magnetic field - one of the forms of more general electromagnetic field .

There are bodies that can create a magnetic field around them (and the magnetic field strength is also valid for such a body), they say that these bodies are logied and have a magnetic moment, which is also determined by the body to create a magnetic field. Such bodies are called magnets .

It should be noted that different materials By divergent to an external magnetic field.

There are materials weakening external field intrabash – paramagnetics and reinforcing the external field inside – diamagnetics.

There are materials with a huge ability (in thousands of times) to strengthen the external field within themselves - iron, cobalt, nickel, gadolinium, alloys and compounds of these metals, they are called - Ferromagnets.

There are among ferromagnets materials that are a sufficient impact on them is a sufficiently strong external magnetic field themselves with magnets - this magnetically solid materials.

There are materials concentrating an external magnetic field and, while the nearest, behave like magnets; But if the external field disappears, they are not unpleasured by magnets - this magnetic materials

Introduction

We are accustomed to the magnet about a bit of a little condescendingly as to the outdated attribute of schooloral physics, sometimes not even suspecting how many magnets around us. In our apartment dozens of magnets: in the electric shaver, speakers, tape recorders, in hours, in jars with nails, finally. We ourselves are also magnets: biotoks current in us give birth around us the fancy pattern of magnetic power lines. Earth, on which we live, - a giant blue magnet. The sun is a yellow plasma ball - magazine more ambitious. Galaxies and nebulae, barely distinguished by telescopes, - incomprehensible size magnets. Thermonuclear synthesis, magnetodynamic generation of electricity, acceleration of charged particles in synchrotrons, raising sunken vessels - all areas where ambitious, unprecedented magnets are required. The problem of creating strong, supreme, ultrasive and even stronger magnetic fields has become one of the main most important physics and technique.

Magnet is known for a man of snow-shy times. We have reached us

about the magnets and their properties of Falez Mieta's tubes (approx. 600 BC) and Plato (427-347 Don.E.). The word "magnet" originated due to the fact that natural magnets Greeks were banned in Magnesia (Fessels).

Natural (or enlightened) magnets are found in nature as deposits of magnetic ores. Valtsky University is the largest known natural magnet. Its mass is 13 kg, and it is able to raise the cargo in 40 kg.

Artificial magnets are magnets created by a person based on various ferromagnetic. Taxable "powder" magnets (from iron, cobalt and some other files) can keep the load of more than 5,000 times greater than their own behavior.

Existing magnets of two different types:

Some - the so-called constricate manufactured from " magnetically solid »Materials. And magnetic properties are not associated with the use of external sources or currents.

The other type includes the so-called electromagnets with a core from " magnetically soft »Iron. The magnetic fields are created mainly by the fact that it takes an electric current on the wire covering the core.

In 1600, the Book of the Royal Doctor was published in London. Hilbert "About magnet, magnetic bodies and a large magnet-land." Etospication was the first idea of \u200b\u200bthe study of magnetic phenomena of science positions known to us. In this work, it was collected then information about magnetism electricities, as well as the results of the author's own experiments.

Of all, with a person who is annoyed, he first of all seeks to extract practical benefits. Unlinked this fate and magnet

In my work, I will try to trace how you are not used by a person not for war, but for peaceful purposes, including the applications in biology, medicine, in everyday life.

COMPASS,the device for determining horizontal directions on the terrain. It is applied to determine the direction in which the marine, airway, ground vehicle; The directions in which pedestrian goes; directions on some object or landmark. Compassuses are divided into dynamic classes: magnetic compasses like shooter, which are used by the imaging and tourists, and non-magnetic, such as gyrocompass and radio compasses.

To 11 c. Referring to the Chinese Shen Kua and Chuu on the manufacture of compasses from natural immughs and using them in navigation. If

the long needle of the antholythomagnet is balanced on the axis, which allows it to turn freely in the horizontal address, then it is always facing one end to the north, and to the other - to the south. The setting pointing to the north, it is possible to use such a compass to the detection of directions.

Magnetic effects confused by the ends of such a needle, and therefore they were called poles (respectively northern and southern).

The main use is magnetic in electrical engineering, radiotechnics, instrument making, automation of ortho gear. Here ferromagnetic materials go on the manufacturer of junction, relays, etc.

In 1820, Earsted (1777-1851) discovered that the conductor runs on a magnetic arrow by turning it. Literally, the ampels showed that two parallel conductor with a current of one directed to each other. Later, he suggested that the unagnificent phenomena were due to currents, and the magnetic properties of permanent motors are associated with currents constantly circulating inside these magnets. Etopropement fully complies with modern ideas.

Electromachine Generos and Electric Motors -machinery type transforming either mechanical energy In electrical (generators), or electrical in mechanical (engines). Impellers are based on the principle of electromagnetic induction: in a wire moving in a magnetic field, an electromotive force (EMF) is guided. ActionElectrodic motors are based on the fact that the wire with a current, an inverse magnetic field is operating.

Magnetoelectrics.In such an appliance, the power of the magnetic field interaction with the current in the turns of the winding part, seeking to turn the last

Induction Power Energy. The induction is meant is nothing but a low-power electric motor transmitted current with two windings - current and voltage winding. Conductor placed between windings rotates under the action of torque proportional to power consumed. This moment is equalized by currents inscribed in the disk by a permanent magnet, so that the frequency of rotation of the discharge of power consumed.

Electric wrist Watch Food miniature battery. For their work, much less details are booked than in the mechanical clock; Thus, there are two magnets, two coils and a transistor in the stem-electric portable clock.

Lock-mechanical, electrical or electronic device limiting the possibility of unauthorized use of anything. Castle can be driven by the device (key) available to the identified person, information (digital or letter code), introduced by an etyl person, or any individual characteristic (for example, drawings of the eye) of this person. The lock usually temporarily connects each other two nodes two parts in one device. Most often, the locks are mechanical, non-wider uses are electromagnetic locks.

Magnetic locks. Magnetic elements are applied by plindle locks of some models. The iconic lock is equipped with response codes of permanent magnets. When the correct key is inserted into the lock query, it attracts and installs the internal magnetic elements of the lock to the descriptive position, which allows you to open the lock.

Dynamometer -mechanical or electrical appliance For measurement of thrust or torque, machine, machine or engine.

Brake dynamometersthere are the most visible constructions; These include, for example, brake penetration, hydraulic is electromagnetic brakes.

Electromagnetic dynamometer It can be filled in the form of a miniature device suitable for measuring characteristic-making engines.

Galvanometer-Content device for measuring weak currents. In the galvanometer, an ongoing moment that occurs in the interaction of a horseshoe-shaped constant, with a small cunning coil (weak electromagnet), suspended with a gap between the poles of the magnet. The torque, and consequently, the reel is proportional to the current and complete magnetic induction in the air transmission, so that the scale of the device with small deviations of the coil is almost linear. The use of its base is the most common type of appliances.

The spectrum of the manufactured devices is widely formulated: Devices panel direct and alternating current (magnetoelectric, magnetoelectric with rectifier and electromagnetic system), combined ampervoltmeter instruments, to diagnose the irregular equipment of the electrical equipment, measuring the temperature of flat surfaces, instruments for equipping school classrooms, testers IMSERTERS of all sorts of electrical parameters

Production abrasivesmall, solid, sharp particles used in free or connected to machining (including to give shape, sprinkles, grinding, polishing) diverse Materials and products from them (from largest plates to sheets of plywood, optical glasses and computer chips). Abrasives are natural or artificial. The effect of abrasives is reduced to the kudania of the material from the surface being processed. The production of the production of artificial abrasives of ferrosilicia, which is present, is settled on the bottom of the furnace, but its small amounts are being introduced into the abrasiveness of it is removed by a magnet.

Magnetic properties of the substance are widely used by Vnaughter and technology as a means of studying the structure of various bodies. So arose science:

Magnetochemistry (magnetochemistry) - section of physical chemistry, in which there is a connection between magnetic and chemical properties substances; In addition, the magnetochemistry explores the influence of magnetic fields into chemical processes. Magnitochemistry relies on modern magnetic phenomena physics. Studying communication magnetic and chemical properties allows us to find out the particular composition of the substance.

Magnetic flaw detector, Defective methods based on the study of the magnetic field distortion arising in places of defects in products from ferromagnetic materials.

. Supervice-frequency range technology

Ultrahigh Frequency Range (microwave) - frequency range of electromagnetic emission (100¸300 000 million Herz), located in the spectrum between ultravylovylovision frequencies and frequencies of far infrared region

Communication.Radio waves of the microwave range are widely shown in communication techniques. In addition to various military radio systems, in all countries of the world there are numerous commercial links of the microwave communication. Commonly, such radio waves do not follow the curvature of the earth's surface, as a rule, these lines, as a rule, consist of a reference stations installed on the tops of hills or on the radio worst Sinter of about 50 km.

Heat treatment of food products.The microwave radiation is for heat treatment of food products at home and in the dietary industry. The energy generated by powerful electronic lamps can be monitored in a small volume for highly efficient thermal processing products in the so-called. Microwave or microwave ovens, differing in cleanliness, silent and compactness. Such devices are applied on inlets, in railway restaurants and vending machines, quick preparation of products and cooking dishes are goggled. Industry is also a microwave oven for domestic purposes.

Fast progress in the field of microwave technology in significant fessessment with the invention of special electrovacuum devices - magnetron iconic, capable of generating large quantities Microwave energy. The generator of the pretentious vacuum triode used at low frequencies in the microwave range is very ineffective.

Magnetron. In the Magnetron, invented in the United Kingdom, the Second World War, these disadvantages are missing, because the basis of a completely different approach to the generation of microwave radiation is the principle of volumetrozonator

In Magnetron, there are several volume resonators, symmetrically located around the cathode located in the center. The device is placed in poles of a strong magnet.

Running wave lamp (LBB).Another electionachamable device for generating and enhancing the electromagnetic VOLSVCH-band is a lamp of the running wave. It is a thin pumping tube inserted into the focusing magnetic coil.

Particle Accelerator, installation in which the directional beams of electrons, protons, ions and other charged faces with an energy significantly exceeding thermal energy is obtained using electrical and magnetic polynets.

In modern accelerators, numerous ways are used, incl. Powerful precision magnets.

In medical studies and diagnosticsthe officers play an important practical role. Throughout the world, many electronic linear accelerators generating intensive x-ray devices, used for tumor therapy, have at their disposal. To lesser extent used proteiclons or synchrotrons that generate proton beams. The advantage of protons of therapy of tumors in front of X-ray radiation is in the coolerocalyse energy release. Therefore, proton therapy is particularly effective in the treatment of brain and eye tumors, when damage to the surrounding healthy tissue to be as minimal.

Representatives of different sciences take into account the magnetic fields of all studies. The physicist measures the magnetic fields of atoms and elementary particles, the astronomer studies the role of space fields in the process of forming a new junction, the geologist for the magnetic field anomalies of the Earth finds the deposits of magnetic, from recently the biology also actively included in the study of the and use of magnets.

Biological sciencethe first half of the 20th century confidently described life functions, at all inconspicuous existence of any magnetic fields. Moreover, nosbiologists considered it necessary to emphasize that even a strong artificial magnetic field does not have any influence on biological objects.

In encyclopedias about the influence of the magnetic fields on biological processes, nothing was said. In the science of all over the world, single positive considerations of Other or other biological effects of magnetic fields appeared annually. However, this weak rod could melt the iceberg distrust even to the formulation of the problem itself ... and the stormy flow turned into a stormy stream. The avalanche of magnetobiological publications, as if having broken down from some vertices, from the beginning of the 60s it is constantly converted and swells skeptical statements.

From the alchemists of the XVIV and to the present day, the biological effect of the magnet many times is completely plans and critics. Repeatedly for several centuries obstacles and decals interest in medical action magnet. With it, they tried to try (and not unsuccessfully) nervous diseases, toothache, insomnia, stuff pain and in the stomach - hundreds of diseases.

For therapeutic purposes, the magnets is used, probably earlier than to determine the parties of the light.

As local outdoor and as amulet, the magnet enjoyed great success among the Chinese, Hindus, Egyptians, Arabs. Greeks, Romans, etc. The philosopher Aristotle and the historian of Pliny are about his medicinal properties.

In the second half of the XXVEK, magnetic bracelets are widely spread, which are beneficially influencing dummy with impaired blood pressure (hypertension and hypotension).

In addition to constant magnets, electromagnets are used. They are also used for a wide range of problems with science, technology, electronics, medicine (nervous diseases, diseases of the limbs, cardiovascular - vascular diseases, CancerBoles).

Most of all, scientists in the idea that magnetic fields increase the body's resistance.

There are electromagnetic measuring velocity of blood flow, miniature capsules, which can be moved along the blood vessels using external grunge fields to expand them, take samples at certain parts of the path or, on the contrary, locally output the various medicines.

The widespread method of removing metal particles from the eye.

Most of us know the heart of the heart using electrical sensors -Electrocardiogram. The electrical impulses produced by the heart, the creator of the heart of the heart, which in MAX values \u200b\u200bis 10-6 stress magnetic field of the Earth. The value of magnetocardiography is that it allows information about electrically "silent" regions of the heart.

It should be noted that biologises are asked to physicists to give the theory of the primary mechanism of the biological effect of the magnetic field, and physicists in response require more provenbiological facts from biologists. Obviously, there will be a successful cooperation between the public specialists.

An important link, unifying vagnetobiological problems, is the reaction nervous system on magnet mention. It is the brain first that reacts to any changes in the external environment. It is that of his reactions will be the key to solving many problems of magnetobiology.

The easiest conclusion, which is one of the above - no area of \u200b\u200bapplied activity, where the magnets would not be used.

References:

1) BSE, the second edition, Moscow, 1957.

2) Colds Yu.A. "Man in Magnet Popeutina", "Knowledge", Moscow, 1972

3) Materials from the Internet - Encyclopedia

4) Putilov K.A. "Course of Physics", "Fizmatgiz", Moscow, 1964.

What is a permanent magnet

The ferromagnetic product capable of maintaining significant residual magnetization after removing the outer magnetic field is called a permanent magnet. Permanent magnets are made from various metalsSuch as: cobalt, iron, nickel, rare-earth metal alloys (for neodymium magnets), as well as from natural minerals such as magnetites.

The scope of the application of permanent magnets is very wide today, but the appointment of them is fundamentally everywhere - as a source of a permanent magnetic field without a supply of electricity. Thus, the magnet is a body with its own.

The very word "magnet" comes from the Greek phrase, which is translated as "a stone from magnesia", by the name of the Asian city, where the deposits of magnetite - magnetic Zheleznyak were opened in antiquity. From a physical point of view, an elementary magnet is an electron, and the magnetic properties of magnets are generally caused by the magnetic moments of electrons included in the magnetized material.

The characteristics of the demagnetizing portion of the material from which a permanent magnet is made are determined by the properties of a permanent magnet: the higher the coercive power of the NA, and the higher the residual magnetic induction of the WR is the stronger and more stable magnet.

The coercive force (literally translated from Latin - "holding force") is necessary for the complete demagnetization of the ferro or ferrimagnetic substance. Thus, the greater coercive force has a specific magnet, it is more resistant to demagnetizing factors.

The unit of measurement of the coercive force - amp / meter. And, as you know, is a vector magnitude that is silence characteristic magnetic field. The characteristic value of the residual magnetic induction of permanent magnets is about 1 Tesla.

Types and properties of permanent magnets

Ferritian

Ferrite magnets are different, but they have good corrosion resistance, which at a low price makes them the most common. Such magnets are made from iron oxide alloy with barium ferrite or strontium. This composition allows the material to maintain its magnetic properties in a wide temperature range - from -30 ° C to + 270 ° C.

Magnetic products in the form of ferrite rings, bars and horseshoes are widely used both in industry and in everyday life, in the technique and electronics. They are used in acoustic systems, in generators, in. In the automotive industry, ferrite magnets are installed in the starters, in windows, in the cooling system and fans.

Ferrite magnets are distinguished by the coercive force of about 200 ka / m and the residual magnetic induction of about 0.4 Tesla. On average, the ferrite magnet can serve from 10 to 30 years.

Alnic (Aluminum Nickel Cobalt)

The constant alloy magnets from aluminum, nickel and cobalt differ in unsurpassed temperature stability and stability: they are able to maintain their magnetic properties at temperatures up to + 550 ° C, although the coercive force characteristic of them is relatively small. Under the action of a relatively small magnetic field, such magnets lose the source magnetic properties.

Judge himself: a typical coercive force of about 50 ka / m with residual magnetization of about 0.7 Tesla. However, despite this feature, Alnic Magnets are indispensable for some scientific research.

The typical content of the components in alcohol alloys with high magnetic properties is varied in the following limits: aluminum - from 7 to 10%, nickel - from 12 to 15%, cobalt - from 18 to 40%, and from 3 to 4% copper.

The more cobalt, the higher the saturation induction and the magnetic energy of the alloy. Supplements in the form of from 2 to 8% of titanium and only 1% niobium contribute to the receipt of greater coercive force - up to 145 ka / m. Additive from 0.5 to 1% silicon provides the isotropy of magnetic properties.

Samarium

If you need an exceptional resistance to corrosion, oxidation and temperatures up to + 350 ° C, then the magnetic spray of samarium with cobalt is what it is necessary.

According to the cost of Samarium-cobalt magnets, more than neodymium due to more deficient and expensive metal - cobalt. However, it is them that it is advisable to apply if necessary to have minimum dimensions and the weight of the finite products.

It is most appropriate in spacecraft, aviation and computer technician, miniature electric motors and magnetic clutches, in wearable devices and devices (clocks, headphones, mobile phones etc.)

Due to the special corrosion resistance, it is the Samarius magnets that are used in strategic developments and military applications. Electric motors, generators, lifting systems, motorcycles - a strong magnet made of samarium-cobalt alloy is ideal for aggressive environments and sophisticated conditions operation. The coercive force is about 700 ka / m with a residual magnetic induction of about 1 Tesla.

Neodymium

Neodymium magnets are currently very in demand and are presented in the most promising. The neodymium-iron alloy allows you to create supermagnets for various spheres, starting with latches and toys, ending with powerful lifting machines.

High coercive force of about 1000 ka / m and residual magnetization of about 1.1 Tesla, allow the magnet to persist for many years, for 10 years neodymium magnet It loses only 1% of its magnetization, if its temperature under operating conditions does not exceed + 80 ° C (for some brands to + 200 ° C). Thus, only two drawbacks have neodymium magnets - fragility and low operating temperature.

Magnetic powder, together with the binding component, forms a soft, flexible and light magnet. Binding components, such as vinyl, rubber, plastic or acrylic allow you to obtain magnets of various shapes and sizes.

Magnetic power, of course, is inferior to clean magnetic materialBut sometimes such solutions are needed to achieve certain unusual targets for magnets: in the production of promotional products, in the manufacture of removable stickers on the car, as well as in the manufacture of various stationery and souvenir products.

The poles of the magnets are repelled, and the multilayen poles are attracted. The interaction of magnets is explained by the fact that any magnet has a magnetic field, and these magnetic fields interact with each other. What, for example, the reason for the magnetization of iron?

According to the hypothesis of the French scientist, inside the substance there are elementary electric currents (amps currents), which are formed due to the movement of electrons around the nuclei of atoms and around their own axis.

When electron movement, elementary magnetic fields occur. And if there is a piece of iron into an external magnetic field, then all elementary magnetic fields in this hardware are oriented in the same way in an external magnetic field, forming a self-magnetic field of a piece of iron. So, if the applied external magnetic field was strong enough, then after it is turned off, a piece of iron will become a permanent magnet.

Knowledge of the shape and magnetization of the permanent magnet allows for calculations to replace it with an equivalent system of electrical and magnetization currents. Such a replacement is possible at the calculation of the characteristics of the magnetic field, and during the calculations of the forces acting on the magnet from the outside of the external field. For example, we will calculate the interaction force of two permanent magnets.

Let the magnets have the form of thin cylinders, their radii we denote R1 and R2, the thickness of H1, H2, the axis of the magnets coincide, the distance between the magnets will indicate Z, we will assume that it is significantly more sizes magnets.

The emergence of the interaction force between magnets is explained in the traditional way: one magnet creates a magnetic field that affects the second magnet.

To calculate the interaction force mentally replace magnets with a homogeneous magnetization J1 and J2 with circular currents flowing along the side surface of the cylinders. The forces of these currents will express through the magnetization of magnets, and their radii will be considered equal to the radius of magnets.

We decompose the vector induction B of the magnetic field created by the first magnet at the location of the second to two components: axial, directed along the axis of the magnet, and radial - perpendicular to it.

To calculate the total force acting on the ring, it is necessary to mentally split it into small IΔL elements and summarize that act on every such element.

Using the rule of the left hand, it is easy to show that the axial component of the magnetic field leads to the appearance of the amps forces, striving to stretch (or compress) the ring - the vector sum of these forces is zero.

The presence of a radial component of the field leads to the emergence of amps forces directed along the axis of magnets, that is, to their attraction or repulsion. It will remain to calculate the forces of the ampere - this will be the strengths of interaction between the two magnets.

First you need to understand what a magnet is in general. Magnet is a natural energy material that has an inexhaustible energy field and two poles, which are called the Northern and South. Although in our time, humanity, of course, learned to create this unusual phenomenon artificially.

The strength of two poles of a magnet man learned to use almost everywhere. Modern society Everyday uses the fan - there are special magnetic brushes in its engine, absolutely every day and to deep night watch TV, work on a computer, and in it enough a large number of These elements. Everyone in the house on the wall hangs hours, all sorts of beautiful small toys on the refrigerator door, the speakers on the whole sound equipment work exclusively thanks to this wonderful magnet.

In industrial enterprises, workers use electric motors, welding machines. In construction used magnetic lifting crane, Iron-separation tape. The magnetic device built into her helps absolutely separating the chips and scale from the finished product. These magnetic tapes are also used in the food industry.

Another magnet is used in jewelry, and these bracelets, chains, all kinds of pendants, rings, seelings, and even hairpins.

Need to understand that without it natural element Our existence will become much more difficult. Many subjects and devices use magnets - from children's toys to quite serious things. After all, not in vain in electrical engineering and physics there is a special section - electricity and magnetism. These two sciences are closely connected. All items where this element is available, immediately and do not list.

Nowadays, new inventions appear increasingly and many of them have magnets, especially if it is associated with electrical engineering. Even the world-famous collider works exclusively with the help of electromagnets.

Magnet is also extensively used for medical purposes - for example, for resonant scanning of human internal organs, as well as surgical purposes. It is used for all sorts of magnetic belts, massage chairs and so on. Healing properties Magnet is not invented - for example, in Georgia on the Black Sea there is a unique resort of Ureki, where the sand is not ordinary - yellow, and black is magnetic. Many diseases are treated there, especially children's cerebrals, nervous disorders, and even hypertension.

More magnets are used on processing enterprises. For example, old cars first put pressure on the press, and then load a magnetic loader.

There are also so-called neodymium magnets. They are used in different areas Industry, where the temperature is not higher than 80 ° C. These magnets are used almost everywhere.

Magnets are now so closely included in our lives that, without them, our life will become very complicated - at the level of the 18-19 centuries. If right now, all the magnets disappeared, we would instantly lose electricity - only its sources such as batteries and batteries would remain. Indeed, in the device of any current generator, the most important part is the magnet. And do not think that your car will start with the battery - the starter is also electrical enginewhere the most important part is a magnet. Yes, you can live without magnets, but at the same time you have to live as our ancestors have lived.

Sooner or later, every woman has a desire to vote his own nest, decorate it with stylish and functional accessories, use the designer decor solution.

Sometimes we do not even guess how else you can use interesting things, the purpose of which, it would seem, is clear. For example, did you know that the dried pumpkin can be closed, and she durable will last you as a vase for the office or field bouquets? BUT watercolor paints Since the growing baby is not worth hiding in a distant box, because they can be uncomplicated to decorate the mirror in the bathroom.

Today we will talk about such cute and useful things of the decor, like magnets. Many of them we bring from travel, trying to keep a piece of memories of a loved place. Other thematic baubles may give us relatives or friends, and the third and at all went from grandmother from time immemorial. It turns out that these small "friends" interior has as many as 10 different ways of use with which we will get acquainted.

1. Element decoration. In most cases, magnets are decorated household appliances like refrigerator or washing machine. Sometimes magnets and letters you can decorate even the Swedish wall. The main thing is at least follow the style. Once I came to visit a friend, and a large number of magnets hang out all over the refrigerator. Next to the improvised sandwiches, you can see the naked torso girls, there are several magnets from Egypt (where they really were), and then with a dozen things of other countries - Vietnam, Tbilisi, Gurzuf, Lviv, London and others. All would be nothing, but when, among this chaos, I saw a couple of bucchok magnets from the yogurt of "Freeshi", surrounded by magnets in the form of weapons, there was no limit to my surprise! If you think that people, being visiting you, do not turn to such trifles as magnets, you are mistaken and risk forever to get a shortcut "tasteless" family that exhibits your "trips and achievements" at the bottom.

2. Photos on the magnet. Few people know that the modern printed industry invented another innovation - personal photos on a flat magnet. Such pleasure is preparing instantly, literally in a few hours, and it will cost quite inexpensive. Not only have you found another way to keep memories, so also the wear of the printed photo on such a dense material is much less. Photos on magnets can be simply removed into the cabinet for careful storage, and you can use them as a decor element - a family tree on an iron bench, for example.

3. Convenient "holding" for entries, as well as fixation. Few families who do not know about such a functional use of the magnet. Even my son at school on modern boards and teacher stands, the teacher consolidates visual material, tables and pictures, without redrawing them manually, as before. In our family, the magnets are an integral details of the refrigerator, because all the tasks on the day, operational telephone numbers, memorial dates And the routine of the day records these small attributes.

As for fixation - my grandfather often used magnets for better adhesion adhesion when eliminating breakdowns or scars on objects. He simply placed the part between two magnets, and faster bonding did not make himself wait.

Mom found another use of the fixing properties of the magnet in the farm - bought a beautiful elongated magnetic strip and clings to it any kitchen appliances (including frying pan and pans). Such bands can be used as knife holders, a mini-magnet can be sewn even into cloth (tap, towel), so that it can be easily located (even attached to the oven).

4. Entertainment for children and adults. On the basis of magnets, many puzzles, fascinating sculptures and instruments for relaxation in the office at a psychologist have long been created. Little kids are especially happy with the items suspended in the air, as well as magnetic cubes, balls, discs and other funny things. Also, the magnets can be issued a "Growth" board for your baby - just celebrate a fun magnet levels to which your child gone for a certain time.

5. Cleaning automotive oil. We are talking On the transmission and motor oil filler. This function of the magnet demonstrated a brother-car mechanic, and she very much went to taste her husband. Compact magnets reliably "plant" on the drain plug of the engine of your machine, and all the elements of the wear of the parts will adhere to them. Powerful magnets will catch only those particles that are abrasive for the material of the parts, and collect them on their surface with which all pollution will be easily removed.

6. Search for items. If your child looked at American films and wants to look for lost gold rings in the resort - it's not worth it to interfere. Once I bought my son a metal detector when he showed the skills of the archaeological researcher. What was my surprise when the fun son began to generate income. For all two weeks of the resort, the son brought 2 gold rings, one pendant and a silver earring for piercing, simply by carrying a thread with an annular magnet on the beach. My husband liked this idea, but it uses it for repair, because with the help of a magnetic "probe" you can quickly find the location of screws, nails and reinforcements in the walls.

Interestingly, there are magnets that can raise objects even from the bottom of the sea weighing up to 300 kg. Immediately played fantasy about underwater pirate claret… But what if?!

7. Repair of musical instruments. My friend's daughter has long been visiting a music school in the class of wind instruments, and her mother has already confused with the legs, trying to find fast way Relo its saxophone and pipe from characteristic dents. It is impossible to get to them on a thin curved tube, and finding the necessary specialist in the repair is not so simple (and pleasure is not cheap). And now she read out somewhere information that the magnet can help in this difficult business. We take the iron ball (better from steel), suitable on the diameter of the tube, and we drive it with an external magnet to the place of dents. Then simply spend the magnet around the perimeter of dents, the ball from the inside will be very attracted to the magnet, the perfectly leveling surface. This repair will cost you very inexpensive and in just a couple of minutes!

8. Fastening iron brooches or badges without traces on clothes. Such interesting way I spied at one of our employees. It regularly walks in elegant silk, satin and chiffon blouses, while the name plate is a mandatory element of the dress code. The girl thoughtfully attach a mini magnet on the outstanding of clothes, and the front would simply lean the badzhik or iron brooch pin to it. Surprisingly, the plate keeps reliably, even on the finest clothes, there is no trace.

9. Element decoration. Many girls heard about the so-called magnetic bracelets made of balls, cubes and other geometric shapes. Such decorations are very quickly gathering, you can make them individual by adding several thematic pendants or registered icons to your assembly. You can also alternate magnetic parts with other elements of decor - leather inserts, sequins, fur, fabric, etc. Also, jewelry made of magnets are considered useful for the body!

Once I watched the program where the girl really wanted to make a fashion piercing to a party, but the parents were not allowed. A guessing girl and herself did not want to "sleep" the body, simply attached a small magnet on one side of the ear of the ear, and on the other hand added 3 silver triangles. This decoration can be made painless, hygienic, quickly and only on those days when you have a mood to wear such a "pattern".

10. Accelerates the fermentation of homemade tinctures. Finally, I'll tell you about an amazing way, with which my friend is preparing liqueurs and wines in their dacha. As he says, placing several magnets to the bottom of the bottle, it creates a powerful field, perfect for fermentation of any alcoholic beverages. A friend claims that maturation occurs several times faster (literally per month), and the drink receives the same taste properties and aromatic bouquets that usually ripen from tinctures in a couple of years of exposure!

Today we reviewed truly amazing ways to use magnets in everyday life. So, if at home you got a couple of magnets, it's time to give them a second life using them for their intended purpose.