What is the difference between the hysteresis loop of hard magnetic material and soft magnetic mater

1. Different properties The hysteresis loop of hard magnetic materials can maintain constant magnetism once magnetized. The hysteresis loop magnetization of soft magnetic materials occurs when HC is not more than 1000A m, and the maximum magnetization can be achieved with the smallest external magnetic field.

2. Different uses The hysteresis loop of soft magnetic material is a typical energy-saving, material-saving, exchange-saving and export-earning product. Soft magnetic materials are easy to magnetize and also easy to demagnetize, and are widely used in electrical equipment and electronic equipment. The most widely used soft magnetic material is iron-silicon alloy (silicon steel sheet.

as well as various soft ferrites, etc.

3. Different advantages Compared with metal permanent magnets, the hysteresis loop of hard magnetic materials has a resistivity.

High, good stability, strong resistance to environmental changes, abundant raw materials, relatively high performance, mature technology, and no oxidation problem. The hysteresis loop saturation of soft magnetic materials has low magnetic flux density and permeability.

Low, low Curie temperature, low mid and high frequency losses, low cost.

4. Different classifications The hysteresis loop of hard magnetic materials is divided into sintered ferrite, bonded ferrite and injection ferrite according to different production processes, and these three processes are divided into isotropic and anisotropic magnets according to the orientation of magnetic crystals. The hysteresis loop of soft magnetic materials is divided into pure iron and mild steel according to their composition.

Soft magnetic material: - Hard magnetic material.

Soft magnetic materials are characterized by high permeability and low coercivity (HC is about 1A m), so the hysteresis loop is elongated;

Hard magnetic materials are characterized by high coercivity (HC>100A m), so the hysteresis loop is wider and the area enclosed is larger.

Magnetic materials are distinguished by the coercivity of the material to belong to permanent magnet materials or soft magnetic materials, and the general standard for distinguishing is: 1-10K

a m.

Hysteresis loopsRepresentationMagnetic field strengthClosed magnetization curve of hysteresis of a strongly magnetic substance when it changes periodically.

The basic magnetization curve is correctMagnetic induction intensityThe maximum value (or magnetic field strength) is taken to a different value, and a series of hysteresis loops are obtained, and the curves connecting the vertices of these loops are called the basic magnetization curves.

The basic magnetization curve, the shape of the hysteresis loop of the ferromagnet is related to the maximum value of the magnetic induction intensity (or magnetic field strength), when drawing the hysteresis loop, if the maximum value of the magnetic induction intensity (or magnetic field strength) is taken differently, a series of hysteresis loops are obtained, and the curve connecting the vertices of these loops is called the basic magnetization curve.

The hysteresis loop represents the closed magnetization curve of the hysteresis of a strongly magnetic substance when the magnetic field strength changes periodically. It shows the relationship between the magnetization intensity m or magnetic induction intensity b and the magnetic field strength h during the repeated magnetization of strongly magnetic substances. Since b = 0(h+m), if the m—h curve of a material is known, its b—h curve can be found, and vice versa.

where 0 is the vacuum permeability.

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Detailed explanation of the initial magnetization curve

Iron, nickel, cobalt and their alloys, which have a high magnetic permeability, are called ferromagnetic substances.

It is the main material that constitutes the magnetic circuit, and the magnetic properties of ferromagnetic substances can be expressed by the magnetic state fiber curve or the b-h curve. The magnetization curve can be obtained by the following experimental method. A piece of ferromagnetic material that has not yet been magnetized (or demagnetized) is made into a toroidal closed core, and a coil is evenly wound on the core, and it is connected to a DC voltage source.

Adjust the resistance r, so that the current from zero and vertical to increase, and the magnetic field strength in the iron core also increases. After measuring the magnetic induction intensity b corresponding to different h values (the magnitude of h can be calculated according to the magnitude of the current), the b-h curve can be plotted point by point. This curve is called the initial (primitive) magnetization curve.

1. The performance is different.

The hysteresis loop of hard magnetic material with material.

Once magnetized, the magnetism remains unchanged.

Soft magnetic materials. The hysteresis loop magnetization occurs when HC is not more than 1000A m, and the maximum magnetization can be reached when the external magnetic field is minimal.

2. Different uses.

The hysteresis loop of soft magnetic materials is a typical energy-saving, material-saving, exchange-saving and export product.

Soft magnetic materials are easily magnetized and demagnetized, and are widely used in electrical and electronic equipment. The most widely used soft magnetic material is iron-silicon alloy (silicon steel sheet.

and various soft ferrites.

3. The advantages are different.

In contrast to metal permanent magnets, the hysteresis loop of a hard magnetic material has resistivity.

It has the advantages of high stability, strong environmental resistance, abundant raw materials, relatively high performance, mature technology, and no oxidation problems.

Soft magnetic materials have low hysteresis loop saturation flux density and low permeability.

Low Curie temperature.

Low mid and high frequency losses, low cost and other advantages.

4. Different classifications.

The hysteresis loop of hard magnetic materials is divided into sintered ferrite, bonded ferrite and injected ferrite according to the different production processes. These three processes are divided into equisquare magnets and equisquare magnets according to the orientation of the magnetic crystals.

The hysteresis loop of soft magnetic materials is divided into pure iron and mild steel according to their composition. Both.

The dynamic magnetization characteristic curve of ferromagnetic materials refers to the b—h relationship orange curve obtained under alternating magnetic field magnetization. That is, dynamic hysteresis loops, dynamic technical magnetization curves, etc.

There is a distinction between dynamic and static magnetization characteristic curve shapes. In the case of hysteresis loops, the shape of the static hysteresis loop is related to the magnitude of the magnetizing field, while the dynamic hysteresis loop is not only related to the magnitude of the magnetizing field, but also to the frequency of magnetization. Different magnetizing fields, different frequencies, and the shape of hysteresis loops tend to be different.

When measuring the static hysteresis loop, only the hysteresis loss exists in the ferromagnetic sample, while when the dynamic hysteresis loop is measured, there is not only hysteresis loss but also eddy current loss in the sample.

This is easy to measure on an oscilloscope. The AC signal waveform between the zero-collapse base axis and the abscissa is the DC component, for example, the zero axis of the AC signal at 5V, that is, the DC component is 5V. The peak value of the AC signal is 2 times the peak value, but it can be directly subtracted from the positive and negative maxima of the AC signal, if the positive maximum is 8V and the negative maximum is 2V, then the peak value is 8-2 = 6V.

To put it simply: the permeability of various ferromagnetic materials and the magnitude of coercivity can be judged through the magnetic retention loop. See which ones are soft magnetic materials and which ones are hard magnetic materials.

Soft magnetic materials are easy to magnetize and demagnetize, suitable for repeated magnetization occasions, and can be used to manufacture transformers, relays, electromagnets, motors and cores of various high-frequency components.

The magnetic permeability of ferromagnetic materials such as carbon steel, tungsten steel, and alnico alloy is not too high, but the coercivity is large, the remanence is also large, and the hysteresis loop is wide and short, and they are called hard magnetic materials. Hard magnetic materials can retain a large remanence after magnetization, and are not easy to demagnetize, which is suitable for making permanent magnets. Like magnetoelectric meters, headphones, small DC motors, and so on.

According to the shape of the hysteresis loop, the ferromagnetic material is often divided into two types: and soft magnetic material.

Correct answer: Hard magnetic material dust; Permanent magnet material.