Can a neodymium magnet demagnetize?

What it is

A neodymium magnet is a magnetic element that is composed of neodymium rare earth boron and iron material. It has a crystal structure, tetragonal shape and formula Nd2Fe14B.

It was first created by General Motors in 1982. It is the strongest permanent magnetic element, the power of which is several times greater than usual. Equipped with a large magnetic induction of 12,400 gauss.

Note! This is a brittle alloy with the formula NdFeB, as well as a hard nickel-plated protective layer and the corresponding class. It is very popular and comes in various forms.

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

Advantages

The most common neodymium magnet is one that has an iron oxide alloy, which has good heat resistance, high magnetic permeability and low cost. Equipped with color coding, high coercivity, powerful magnetic field to hold objects suspended, compact size, light weight, affordable and wide range of applications. Has a long service life.

If an ordinary magnet works for 10 years and can be demagnetized, then a neodymium magnet does not lose its properties after 100 years. Another advantage is the shape. This product has a horseshoe shape. It gives the device a long service life. As for the cost, these are expensive products, but the cost is justified by excellent performance and impeccable reliability.

It is worth pointing out that the strength contained in neodymium magnets is another advantage. She is tall and it is impossible to find a competitor to her. This is a record type of indicator, the increase of which is impossible. Power is generated during manufacturing. Magnetization occurs after the alloy is formed. Thanks to existing technologies, the alloy is magnetized in such a way that the magnet has incredibly high power and this figure reaches a record.

Note! Power is a relative philistine concept. The force is stable, but it is measured using instruments. In this case, the readings depend on the thickness of the surface and cleanliness. The separation angle can have some influence.

Life time

The service life of the equipment, if used properly, is 30 years. Due to careless handling, the device may be damaged. The point is the lack of flexibility, as well as brittleness and cracking under heavy load. Falls, impacts, or reduced traction will reduce the life of the equipment. For this reason, it is necessary to avoid falls using parts that come into contact during movements.

Another extremely important point is the irreversible loss of magnetic properties due to heating. Therefore, grinding with cutting or drilling reduces the chain force and may ignite the alloy. If storage and operation are organized correctly, then magnetization is maintained for 10 years.

What is neodymium

The product, which is now used everywhere, is an alloy of several metals, including rare earth ones. Since one of them, the main one, is neodymium (Nd), the invention was named after it. Today you cannot do without it either in everyday life, or in production, or in medicine, or in electrical engineering.

Unlike the ferrite product, neodymium comes in a variety of forms:

• washers;
• rings;
• plates;
• rectangles.

The shape does not affect the strength and properties of neodymium, and this is another advantage. Another undeniable advantage is service life.

Design

When answering the question of what a neodymium magnet is made of, we can point out that it is a rare earth element that contains an atom with lanthanide or actinide. The classic composition may still contain an additive. It is used to increase strength with endurance and resistance to high temperatures. Boron is used in small quantities, iron is a binding element. Thanks to this composition, greater adhesion is obtained. When connecting several ferrite rings, you can separate them with your hands. As for neodymium magnets, this cannot be done.

Scope of application of neodymium magnets

Neodymium magnets have almost completely replaced ferrite magnets in many applications, including industrial applications, as they are much stronger while being more compact.

Thus, neodymium magnets have found the following applications:

• in computer hard disk drives
• as part of erasing heads of inexpensive equipment
• in magnetic resonance imaging (MRI)
• in magnetic guitar pickups
• in electronic cigarettes
• in door locks
• in loudspeakers and headphones
• in magnetic bearings
• in NMR spectrometers
• in electric motors
• in cordless tools
• in servomotors
• in lifting and compressor engines
• in stepper motors
• in electric power steering
• on hybrid and electric vehicles
• in generators and turbines (direct drive turbines require 600 kg of magnets per megawatt of power, and 31% of this mass is neodymium)

How to use

Neodymium magnetic element is the strongest, exceeding analogues that are based on rare earth metal. In addition, neodymium is capable of maintaining a magnetized structure for a significantly long time. Such equipment can be used in various fields. For example, it is used in the manufacture of over-ear headphones with wind generators, motor wheels and scooters.

Note! Magnets are actively used in industrial, household, and medical fields. They are also used to carry out search work with a metal detector. They can often be found in plumbing fixtures or souvenirs.

Specific examples include the use of magnets in the development of medical devices, magnetic treatment of water, the creation of oil and technological filters, and the formation of actuators with highly sensitive sensors. In addition, they are needed to produce clothes with covers and shoes, and to create advertising, information and navigation materials.

Overall, neodymium is the most powerful permanent magnetic material that has high resistance to demagnetization, attractive power, and a metallic appearance. It has a long service life and consists of boron, iron and a metal of the lanthanide group.

The online store magnitstore.ru sells neodymium magnets, the adhesive force of which is ten times higher than their ferrite counterparts. There are universal products such as disks, rectangles, rods, rings. And targeted ones: search engines, mounts, car holders and others. All products, while relatively small in size, are very powerful. I would like to know what kind of field these strong neodymium magnets create and where does it even come from?

How to place an order

Basically, such products are used in agriculture, industry, in the production of toys, souvenirs, in the manufacture of medical equipment, and in electronics. Neodymiums work well as various holders and clamps. For private use, you can order a neodymium magnet by mail through specialized online stores. This is very convenient and profitable, since the prices are not inflated, and the managers will always help you place your order and answer any questions you may have.

When planning to order a neodymium magnet by cash on delivery, indicate exactly which products you want to purchase and your address: the products you are interested in will be delivered soon.

The two-color horseshoe, familiar from school times, which attracted all metal objects in physics lessons, is not so relevant today. The previous magnet was not so strong. Nowadays, powerful neodymium magnets are very popular, the service life of which is many times longer than the service life of conventional ones.

Magnetic susceptibility

To understand why such a strong neodymium magnet and where its magnetic field comes from, you need to understand (without delving into complex formulas and graphs) at least the basic physical concepts of permanent magnetization.

Let's start with magnetic susceptibility. This is the name of a dimensionless quantity (denoted c), which characterizes the ability of a substance to be magnetized after it is in a force field. (By the way, the magnetic field of a neodymium magnet is such that it itself can magnetize products made from other alloys).

How to demagnetize an electric meter after a magnet

The sensor is capable of transmitting information over a distance of 10 km in urban areas. Moreover, it operates from an autonomous power source (about 10 years). By the way, an attempt to install a neodymium magnet on such a meter is immediately recorded and sent to the dispatcher. Therefore, this meter model is not in demand among unscrupulous residents. How can controllers find out everything? A trivial situation is when your experiments led to a complete stop of the water meter. Everything is simple here. You will have to call water utility employees to unseal and replace the water meter. The inspector will understand the reason and issue an administrative protocol. Moreover, even if you succeed, inspectors will still be able to determine whether you are using a magnet. We do not take into account the moment when you were caught red-handed. Everything is simpler here. When you have a magnet on a water meter, its body becomes magnetized. Since the heating element in the iron is somehow made in the shape of a spiral, when connected to the electrical network it turns into a coil, when a current passes through it, a magnetic field is formed and to remove residual magnetization you need to do the following. At a considerable distance from the meter, plug the iron into the socket and, using slow circular movements, bring it closer to the meter and just as slowly move it away from the meter to the maximum distance, after which turn off the iron from the network. These slow passes with an iron will remove residual magnetization, just like a special loop that demagnetizes a TV picture tube or computer monitor screen. The main condition: you need to turn the iron on and off at the maximum distance from the product for demagnetization.

Read also: Tool for fastening profiles for drywall

Magnetization

Numerically, magnetic susceptibility is equal to the magnetization of a substance at unit field strength. Magnetization (denoted by J) characterizes the magnetic state of a particular physical body. If it is placed in a force field, then it will receive a certain magnetic moment M. In this case, its magnetization will be equal to the magnetic moment of a unit volume V. If the body is uniformly magnetized, then J = M/V. Magnetization is directly proportional to the strength of the force field that caused it. At one stage in the production of NdFeB products, they are placed in a very powerful force field, which gives greater magnetization. Therefore, the neodymium magnet has a simply enormous grip.

Magnetic moment is a vector characteristic of a substance that is a source of a magnetic field. (If, for example, an ingot of iron is brought into a force field and magnetized, then it itself will become a source of magnetism). It is created by the magnetic moments of elementary particles (atoms), which have an ordered orientation in space and therefore add up. The strength of a neodymium magnet is great, in part because it has a significant magnetic moment.

Magnetic induction

The value of the residual magnetic induction (designated Br) allows you to understand how dense the power flux or how strong the magnetic field is produced by a given magnet in a closed system. Magnetic induction (designation B) is the reading of a gaussmeter obtained by measuring the power of the force field on the surface of a particular magnet. Both quantities are expressed in Tesla or Gauss (1 Tesla = 10,000 Gauss). Since the magnetization of a neodymium magnet is significant, its magnetic induction is also high, from 1.0 to 1.4 Tesla. For comparison, ferrites have from 0.1 to 0.4 T.

The volumetric magnetic susceptibility of any substance is numerically equal to the magnetization of its unit volume divided by the strength of the magnetizing force field: c = J/H. Paramagnetic materials have positive magnetic susceptibility because the direction of the molecular current field coincides with the direction of the external force field. (For diamagnetic materials it is the other way around).

Magnetization of paramagnetic materials

A neodymium magnet, whose adhesive force is so strong, is paramagnetic. It has positive magnetic susceptibility. In its normal state it does not have any noticeable magnetic properties. The reason is this. In it, like in other paramagnetic materials, the magnetic moments are compensated because there is no ordered arrangement of elementary particles. That is, in the case when there is no external magnetizing field, each neodymium atom still has some kind of “microscopic” magnetic moment. But neodymium does not have the same structure that is inherent in ferromagnets. Therefore, the atoms are randomly oriented, the magnetic moments are directed in different directions. The vector addition of their numerical values ​​results in zero, which means that the magnetization of the entire ingot is also zero. How is it that neodymium magnets have such a strong attractive force?

Everything is very simple. When a paramagnetic material enters an external magnetic field, its atoms turn (orient) in one direction. After which the vector addition of unit moments will no longer be equal to zero. As a result, neodymium receives a total magnetic moment J. It is directly proportional to the external field strength H and directed along this field. When making a neodymium magnet, a magnetic field for its magnetization is created with an induction of about 3 - 4 Tesla.

There is one important point that is useful to know for those who are interested in the properties of NdFeB. The magnetic ordering of atoms is counteracted by the thermal energy of the substance. Despite the fact that neodymium magnets develop a very large force, the paramagnetic susceptibility of the main element Nd largely depends on temperature. This is why the NdFeB alloy cannot be heated to + 80 degrees C and higher - the atoms will lose orientation and the vector sum of their magnetic moments will again become zero.

This is the explanation of why neodymium magnets have an attractive force at all, and even such a large one. The two main points are that Nd is paramagnetic and a large force field is created to magnetize it. This is, of course, a simplified view. To understand why a neodymium magnet is reinforced with iron and boron, you need to master quantum physics.

We wrote this article to answer the question about classes of magnets, their standards, and physical characteristics.

Despite the fact that the magnets we offer are called neodymium, they can be very different from each other, because each magnet has its own physical characteristics, not just size, shape and coating. Therefore, the question of which neodymium magnets are of interest to you should not confuse you. In this article you will get answers to many of your questions.

How to magnetize a screwdriver at home: tips, methods

In order for repairs, installation and other work to proceed quickly and efficiently, nothing should interfere, especially if it is a small screw that tends to fall off the screwdriver. For convenience, you can buy a special analogue with a magnetic tip.

But don’t throw your regular screwdrivers in the trash, because you can make these out of them too. To do this, most craftsmen use magnetizers, but there are also other ways to make such a miracle screwdriver. And for this you don’t need services, everything can be done easier and faster. Read on to learn how to magnetize a screwdriver at home.

Screwdriver magnetizers

A screwdriver with a magnetic tip is, of course, good, but in some situations it can, on the contrary, interfere or even cause harm. For example, when working with electronics, a magnet can cause serious and irreparable damage to some parts.

And constantly juggling screwdrivers is quite stupid and inconvenient. Therefore, most craftsmen who often have to use a screwdriver use a special device, a magnetizer. With it you can quickly magnetize and demagnetize the tool without much manipulation.

Previously, such a service could be performed in workshops, but now, with the arrival of this device, there is no longer a question of how to magnetize a screwdriver at home.

Magnetizers are simple in design and use, which can change the corresponding parameter of metal objects. A huge advantage of the device is that it does not require additional connection to the network or recharging. And the small dimensions allow you to always have such a useful thing with you. And if we consider the design itself, the magnetizer consists of:

• polymer case with slots for metal objects;

• a set of magnets of different polarities.

Each of these holes is responsible for one or another function, magnetization, demagnetization. Usually, the slots are labeled, but even otherwise, you can very quickly check the parameters of each compartment.

The principle of operation is incredibly simple: place the object in the desired hole, wait a little. These devices differ in the size of the instrument itself and the size of the incision. The second parameter depends on how large the object needs to be magnetized.

They do not vary much in price, the usual price per piece varies from 100 to 400 rubles, although more expensive models can be found. Whether they are worth the money is up to everyone to decide.

How to magnetize a screwdriver without a magnetizer

As in the case of a special screwdriver, a magnetizer can become unnecessary and an unjustified waste of money and time. This is especially true in cases where the need for a magnetized screwdriver is extremely rare.

And then there is a need to find a handy way to solve the problem. There are several methods on how to magnetize a screwdriver at home without using the device described above:

• Using a powerful magnet. If there is such an item, then you can bring the instrument to the desired state in a few minutes. You need to move the screwdriver from the tip to the middle with a magnet. If you always need such a tool, then after work you can leave it on the magnet.

• Using an improvised reel. In cases where there is no good magnet, and you need a screwdriver right now, you can make the missing item yourself. To do this, you need to wrap a metal object with paper and varnished copper wire.

For a good result, the wire will need a lot, two to four hundred turns around the selected object. The result is a coil to which voltage must be applied. To do this, you can use a battery, batteries, charger, and so on.

• Through the voltage of the household, general power supply network. The same coil is also used here, only the voltage is supplied from the outlet. An important difference is the presence of a fuse that can protect against short circuits. You should be especially careful, because when connected, the fuse will burn out.

Each of these methods should be done following safety rules, otherwise it can cause harm to health. It is best if you do not have the appropriate skills or knowledge to seek help or advice from a person knowledgeable in this area.

Otherwise, each of these methods will be able to magnetize any metal object. The cheapness of each method should be considered individually, based on the availability of the necessary components.

video on how to magnetize and demagnetize a tool without special equipment

Conclusion

It is quite simple to bring a screwdriver to the desired state, both using a magnetizer and without it. The most important thing with the second option is to remember the risks and prepare the workplace accordingly, to protect yourself.

If there is uncertainty about the success of the artisanal method, the best, economical solution would be to purchase a magnetizer. And remember that in some cases, excessive magnetic properties can be harmful to operation, especially when working with electronics.

Source: https://prosto-instrumenty.ru/kak-namagnitit-otvertku-v-domashnix-usloviyax/

What do the letters and numbers mean in the classes of neodymium magnets?

Often, we, as manufacturers and sellers, want to hear the technical characteristics of the magnet, namely the letters and numbers in which they (the technical characteristics) are encrypted. And the buyer often thoroughly knows his field of application of magnets, but does not know the nomenclature, especially the international one. So, let's begin to understand the international nomenclature of magnets, namely classes, technical characteristics and designations.

First of all, neodymium magnets are divided into classes, which are designated by letters and numbers (for example, N35), which contain basic information about the magnet. Below is a standard nomenclature table of characteristics of neodymium magnets (look in the left column - the classes are indicated there).

In the table, we presented all numerical values ​​in two units of measurement. The first, without brackets, is the measurement value in the SI system (this is the system in which our country operates), and the second (indicated in brackets) is the measurement in the international CGSE system (European standards). For your convenience, we decided to indicate both units of measurement in the table.

Neodymium magnet characteristics table

We begin to study the table from right to left. As you can see from the right column of the table, the main class difference between magnets is their operating temperature of use, that is, the permissible maximum temperature, above which the magnet begins to lose its magnetic properties. Thus, the temperature range of use of the magnet is indicated by the letter part of its marking (left column). Let's decipher these letters:

• Magnets brand N (Normal) – can be used at normal temperatures, that is, up to 80 degrees Celsius;
• Magnets brand M (Medium) – can be used at elevated temperatures, that is, up to 100 degrees Celsius;
• Magnets of grade H (High) – can be used at high temperatures, up to 120 degrees Celsius;
• SH (Super High) magnets
• Magnets of the UH (Ultra High) brand – can be used at temperatures up to 180 degrees Celsius;
• Magnets brand EH (Extra High) - can be used at temperatures up to 200 degrees Celsius.

It is worth mentioning that negative temperatures do not affect the magnetic properties of most magnets.

The numbers indicated in the magnet class designation: N30, 33M, 35H, 38SH, 40UH, etc., indicate Magnetic Energy (fourth column of the table), measured in kiloJoules per cubic meter. This criterion of magnets is responsible for their power or the so-called “tearing force,” that is, the force that must be applied to the magnet in order to “tear” it from the surface. It is necessary to understand that the surface (steel sheet) must be perfectly flat, and the applied force must be perpendicular to the sheet. These are the so-called ideal or theoretical conditions. It is absolutely clear that the higher the digital designation of the magnet, the higher its pull-out force.

Where to buy a neodymium magnet?

Neodymium magnets of various shapes, sizes and holding forces are offered by the company, whose central store-warehouse is located in St. Petersburg. To familiarize yourself with the range and detailed technical characteristics of magnetic products made of neodymium, we suggest following the link.

Types and shape of neodymium magnets

Types of magnets available for ordering through the website:

• disks;
• rings;
• rectangles;
• squares;
• rods (cylinders);
• discs and plates with a countersunk hole for a screw.

A neodymium disk is a universal form of magnetic fastener that has an adhesive force of up to 55 kg and is used as a holder or retainer. Its variety - a disk with a hole for a self-tapping screw - is used when it is necessary to fix a magnetic holder on a wooden, plastic or concrete surface (wall, cabinet, panel) for subsequent storage of keys or other small iron items.

Magnets in the shape of a ring (washer) have found application in souvenirs, advertising products, products with magnetic locks and clamps. They can be tied to a rope and used to clean liquids and bulk products, and search for hardware in water. Magnets rods (rods) and rectangles are widely used to create household magnetic fasteners, door latches, as well as in modeling, advertising, and electronics.

Most consumers buy neodymium magnets in China, since this country is the leader in the extraction and production of neodymium. Today there is no need to order them on AliExpress and wait a long time for delivery. Wholesale delivers these products to Russia, and the price of neodymium magnets is no higher than on the Chinese website. Small disk magnets with a diameter of 3 to 10 mm can be purchased at prices ranging from 5 to 20 rubles. Medium models with a diameter of 20-30 mm will cost no more than 100 rubles. The cost of the most powerful and largest magnets does not exceed 2000 rubles.