Why do magnets lose their magnetism at high temperatures?

Magnets are magnetic because of iron, cobalt, nickel, or ferrite.

Other ferromagnetic substances differ from the spin of electrons inside it.

It can be arranged spontaneously in a small area, forming a spontaneous magnetization zone, which is calledMagnetic domains

After the ferromagnetic material is magnetized, the internal magnetic domains are arranged neatly and in the same direction, so that the magnetism is strengthened, and the magnet is formed. The process of magnet iron attraction is to the iron block.

The magnetization process produces an attractive force between the magnetized iron block and the magnet with different polarities.

The iron is firmly "glued" to the magnet. Let's say that magnets are magnetic. However, high temperatures change this particular internal structure, resulting in the loss of magnetism.

The principle of the magnetic field of celestial bodies is different, and in layman's terms, it is because the surface of the celestial body is charged with gas (the sun) or the interior is charged with magma.

Earth) (of course, the above is only the most accepted hypothesis, and is inconclusive, and is only used here to distinguish it from magnets).

Personally, I think that magnets do lose their magnetic physical phenomena in the ultra-high temperature stateIn fact, it only loses the part of magnetic opposite-sex attraction in the ultra-high temperature state, and the same-sex repulsion and magnetic field coil in the magnetism still exist.

Because, in the universe, all visible physical matter is made up of atoms, and the atoms are subdivided into nuclei.

It is composed of many electrons on the periphery.

The phenomenon of infinite natural circulation of electrons around the nucleus of the atom will naturally produce the magnetic physical phenomenon of the atoms of the solid substanceIn other words, all celestial bodies in the universe naturally have their own magnetic phenomena.

The electromagnet burns red, and the molecules inside it heat up all over the place, disrupting the consistency of the direction of electron motion.

Magnetism is ordered, and high temperature is the intensification of particle motion, and the order of magnetism is broken by a certain program, and magnetism is gradually lost with the increase of temperature.

Because the high temperature will interfere with the magnetism inside the magnet.

Whether it is ferrite, rare earth, alnico permanent magnet materials will lose their magnetism due to accelerated thermal movement at high temperatures.

The magnetic effects cancel each other out, so the whole "magnet" no longer shows magnetism.

The high temperature can cause problems on the inside of the magnet.

Because high temperatures are devastating for magnetic damage.

The molecules in the magnet are destroyed.

At high temperatures, there is a molecular disorder in the magnet.

Because the high temperature will inactivate the magnet.

It can throw the neatly arranged molecules out of balance.

High temperature resistance.

The composition of the magnet is iron, cobalt, nickel and other atoms, and the internal structure of the atoms is relatively special, and it itself has a magnetic moment. Magnets are capable of generating magnetic fields and have the property of attracting ferromagnetic materials such as iron, nickel, cobalt, and other metals.

Magnet type: shape magnet: square magnet, tile magnet, special-shaped magnet, cylindrical magnet, ring magnet, disc magnet, magnetic rod magnet, magnetic stand magnet, attribute magnet:

Samarium cobalt magnets, NdFeB magnets (powerful magnets), ferrite magnets, Alnico magnets, iron-chromium-cobalt magnets.

Application in traditional industry:

When talking about the magnetism**, electromagnetic induction, and magnetic devices of magnetic materials, we have already mentioned the practical applications of some magnetic materials. In fact, magnetic materials have been widely used in various aspects of traditional industries.

For example, without magnetic materials, electrification would not be possible because generators are used to generate electricity, transformers are used to transmit electricity, electric motors are used in electrical machinery, and loudspeakers are used in electric machines, radios, and televisions. Many instruments and meters use magnetic coil structure. This has already been said in the context of other things.

1.Whether the magnet can withstand high temperatures is determined by the characteristics of the raw material of the magnet.

2.The so-called high temperature refers to the temperature phase of 120-180-200-250-300-350-400 degrees.

3.At present, high-temperature resistant materials on the market are relatively popular.

4.Ferrite temperature resistance 80 degrees Rare earth NdFeB temperature resistance is 120, 180 degrees.

5.Samarium cobalt temperature resistance 250 degrees Celsius and 350 degrees.

6.Iron, chromium and cobalt are temperature resistant to 400 degrees.

7.There are also higher temperature-resistant materials, aluminum-nickel-cobalt, with a temperature resistance of 600 degrees.

8.There are two important parameters for the requirements of the magnet, such as magnetic force and temperature resistance range, and then the material of the magnet can be selected according to the use environment to meet the purpose of use.

The magnetism and temperature of the magnet are negatively correlated, the stronger the magnetism, the lower the temperature resistance, such as NdFeB (200), samarium cobalt (250-350); The weaker the magnetism, the higher the temperature resistance, such as ferrite (500-600), alnico (500-600). For now, that's right.

The reason why there is a magnetic field around the magnet is because there are positively charged nuclei and negatively charged electrons in the atoms of the magnet, and when the electrons move around the nucleus in the atoms, a toroidal current will be formed, and when the direction of the toroidal current generated by the electrons in the atoms is the same, and the orbits of these electrons remain unchanged, then a magnetic field will be formed around this substance.

The high temperature will accelerate the motion of the molecules in the magnet, thus changing the direction of its original molecular current, which in turn will change the overall magnetic properties and weaken it to disappear. After heating, the direction of the movement of the electrons is different and chaotic, and the magnetic effect cancels each other out.

The process of degaussing involves heating beyond the Curie point, applying a strengthened magnetic field, applying alternating current, or hammering the metal, and over time, degaussing occurs naturally.

When the temperature reaches more than 100°C, it will be demagnetized, and the working temperature is different depending on the material. The working temperature of NdFeB magnets can reach up to 200 degrees Celsius, and the working temperature of Alnico magnets can reach more than 600 degrees Celsius. <>

1.Whether the magnet can withstand high temperatures is determined by the characteristics of the raw material of the magnet.

2.The so-called high temperature refers to the temperature phase of 120-180-200-250-300-350-400 degrees.

3.At present, high-temperature resistant materials on the market are relatively popular.

4.Ferrite temperature resistance 80 degrees Rare earth NdFeB temperature resistance is 120, 180 degrees.

5.Samarium cobalt temperature resistance 250 degrees Celsius and 350 degrees.

6.Iron, chromium and cobalt are temperature resistant to 400 degrees.

7.There are also higher temperature-resistant materials, aluminum-nickel-cobalt, with a temperature resistance of 600 degrees.

8.There are two important parameters for the requirements of the magnet, such as magnetic force and temperature resistance range, and then the material of the magnet can be selected according to the use environment to meet the purpose of use.

The magnetism and temperature of the magnet are negatively correlated, the stronger the magnetism, the lower the temperature resistance, such as NdFeB (200), samarium cobalt (250-350); The weaker the magnetism, the higher the temperature resistance, such as ferrite (500-600), alnico (500-600). For now, that's right.

To put it simply, the principle of magnetic field generated by magnets is different from that of the earth. Below, let's introduce how the two types of magnetic fields are generated.

In atoms, whether it is the spin of electrons, protons, or the movement of electrons in orbits outside the nucleus produces the corresponding magnetic moments. If the magnetic moment in the atom cancels out completely, then the substance does not produce a magnetic field, so it does not exhibit magnetism and is not a magnet. And if the magnetic moments in the atoms are superimposed, there will be a net magnetic moment, then the substance will produce a magnetic field, thus exhibiting magnetism, which is the magnet.

In the magnetic field generated by a magnet, a ferromagnetic substance such as iron is magnetized, causing a strong electromagnetic force between the magnet and the ferromagnetic material, thus showing that the magnet can attract ferromagnetic materials.

When the temperature exceeds a certain critical temperature, the magnetic properties of the magnet will disappear due to the intensification of the thermal motion of the atoms, resulting in the arrangement of the atomic magnetic moments of the magnet from order to chaos, and this critical temperature is called Curie temperature. The Curie temperature of the more common ferrite magnets is about 450 degrees Celsius, and the neodymium iron boron magnets is about 310 degrees. If the temperature is lower than the Curie temperature, the object regains its magnetic properties.

On the other hand, although the temperature of the Earth's interior is very high, with the Earth's core temperature reaching up to 5,500 degrees, the Earth's interior still generates a magnetic field and does not demagnetize. According to the current mainstream theory, although the Earth's magnetic field is similar to that of a rod magnet, the Earth is not a "magnet", but a "generator".

The top layer of the Earth's interior is a thin crust, with the mantle 2,890 kilometers thick and the core 3,400 kilometers thick. At the junction of the mantle and the core, temperatures can reach up to 4800 degrees, which allows the core, which consists mainly of iron and nickel, to melt into a liquid state. But as the depth increases, the pressure rises dramatically, causing iron and nickel to become solid.

Thus, the Earth's core consists of a liquid outer core, which is 2,200 kilometers thick, and a solid inner core, which is 1,200 kilometers thick.

During the rotation of the Earth, the rotation speed of the inner and outer cores is different, and the liquid iron and nickel in the outer core flow through the initial magnetic field (the solar magnetic field), which will generate an electric current through electromagnetic induction, so that the newly generated electric field will in turn produce a magnetic field. As a result, the magnetic field generated by the principle of the Earth's nuclear generator does not disappear in a high-temperature environment.

When we put the magnet on the fire, the thermal movement of the atoms inside the magnet will become more and more intense with the increase of temperature, and the direction of "micromagnetism" will also change, when the temperature rises to a critical value, these "micromagnetic" will become very chaotic, which will cause their magnetic fields to cancel each other, so that they no longer show magnetism externally. This cut-off value is called the "Curie temperature", and according to the measurement, the "Curie temperature" of our common magnets (ferrite magnets) is 450 degrees Celsius.

1.Whether the magnet can withstand high temperatures is determined by the characteristics of the raw material of the magnet.

2.The so-called high temperature refers to the temperature phase of 120-180-200-250-300-350-400 degrees.

3.At present, high-temperature resistant materials on the market are relatively popular.

4.Ferrite temperature resistance 80 degrees Rare earth NdFeB temperature resistance is 120, 180 degrees.

5.Samarium cobalt temperature resistance 250 degrees Celsius and 350 degrees.

6.Iron, chromium and cobalt are temperature resistant to 400 degrees.

7.There are also higher temperature-resistant materials, aluminum-nickel-cobalt, with a temperature resistance of 600 degrees.

8.There are two important parameters for the requirements of the magnet, such as magnetic force and temperature resistance range, and then the material of the magnet can be selected according to the use environment to meet the purpose of use.

The magnetism and temperature of the magnet are negatively correlated, the stronger the magnetism, the lower the temperature resistance, such as NdFeB (200), samarium cobalt (250-350); The weaker the magnetism, the higher the temperature resistance, such as ferrite (500-600), alnico (500-600). For now, that's right.