Soft magnetic alloys play an important role in modern industry. Their unique magnetic properties are in demand in electronics, electrical equipment and other high-tech industries. In this article, we will consider the main parameters, physical principles of operation and characteristics of materials produced by the PZPS plant.
Main parameters and concepts
Magnetization (I) — reflects the degree of magnetic state of the material and is measured as the magnetic moment per unit volume of material. This vector quantity is directed along the lines of the external magnetic field and is closely related to the field strength.
- Magnetic moment characterizes the intensity and direction of magnetic action, determining the ability of the material to create or change a magnetic field.
- Magnetic field strength (H) shows how much force an external field acts on moving charges or magnetized bodies.
- Magnetic induction (B) reflects how the material is magnetized under the influence of an external field.
These parameters form the basis for analyzing the magnetic properties of various materials. The difference between ferromagnets, diamagnets and paramagnets is largely determined by the magnitude of these characteristics.
Magnetization vector (J) describes how strongly the material is able to respond to an external magnetic field. For different types of materials, this response can vary significantly:
- y ferromagnets magnetization remains even after the external field is removed;
- paramagnets they have a weak positive magnetization, which disappears when the field is removed;
- diamagnetics have negative magnetization directed against the external field.
The magnetization vector is used in electromagnetism to describe the interaction of a magnetic field with materials, including for analyzing the magnetic properties of steels and alloys (for example, in electronics and instrument engineering), calculating magnetic circuits and magnetic screens, describing processes associated with hysteresis and magnetic saturation.
Magnetic induction and material properties
Magnetic induction determines the strength and direction of the magnetic field on the material. Its value depends on the properties of the substance:
- Ferromagnetic materials, such as iron, nickel, cobalt and numerous alloys of these metals have high magnetic induction due to their significant magnetic permeability. After removing the external magnetic field, a significant part of the magnetization (residual magnetic induction) is retained. To demagnetize a ferromagnet, a certain reverse field, called coercive force, is required.
- Paramagnets — many iron salts, rare earth elements, platinum and palladium group metals, sodium, potassium, oxygen and ferromagnets at temperatures above the Curie point. They have weak positive magnetization that does not cause noticeable hysteresis — a delay in changes in magnetic induction relative to changes in the intensity of the external magnetic field. Their permeability does not depend on the external field and either does not depend on temperature at all, or decreases with increasing temperature.
- Diamagnetic materials demonstrate magnetization directed opposite to the external field, with a permeability below one. When they enter the magnetic field, they push towards the weaker field. Many metals and most non-metals are diamagnets. Unlike paramagnetic and ferromagnetic materials, diamagnetic properties are practically independent of temperature.
These diversities determine the applications of materials, from precise measuring instruments to powerful electromagnets.
Magnetization characteristics
The process of magnetizing materials in an external field is described by key characteristics:
- Magnetization curve — a graph showing how the material reacts to changes in magnetic field strength.
If a non-magnetized iron sample is placed near a magnet or an electric current is introduced into the magnetic field, it is magnetized. The magnetization of a material in an external field is described by a curve representing magnetization I or induction B in the sample as a function of the external field strength H. These curves are of fundamental importance in describing the magnetic properties of materials. - Hysteresis loop — reflects residual magnetization (at H=0) — the material's ability to maintain magnetization after removing the external field, and coercive force (at B=0) — the amount of field strength at which magnetic induction becomes zero during demagnetization. It characterizes the ability of the material to maintain a magnetic state.
These parameters are important when choosing material for devices, where high resistance to demagnetization or a stable retention of the magnetic state is required.
Magnetic permeability
Magnetic permeability shows how effectively a material enhances the magnetic field.
- Initial permeability (when B and H tend to zero) is measured at weak external fields and reflects the behavior of the material in the initial stage of magnetization.
- Maximum permeability is achieved under optimal conditions and demonstrates the peak of material efficiency.
These parameters determine the applications of soft magnetic materials, from transformers to measuring devices.
Magnetostriction
Magnetostriction is a change in the size of a material under the influence of a magnetic field.
- Linear magnetostriction is expressed as a change in sample length along the field.
- Volumetric magnetostriction characterizes the overall change in volume. For most materials, the relative change in body volume during magnetization is significantly less than the relative change in length.
The magnetostriction effect is important for designing devices where the magnetic field affects mechanical deformation, for example, in ultrasonic transducers or actuators.
Soft magnetic alloys from the PZPS plant
The factory PZPS produces electrical steels 20895, 20880, 20860, 20832, 21895, 21880, 21860, 21832, and also offers a wide range of soft magnetic materials with unique characteristics:
- 50N — high magnetic permeability, suitable for transformers and electromagnets;
- 50NP — alloy with a rectangular hysteresis loop, used in pulse technology;
- 79NM — high permeability in weak fields, used in precision instruments;
- 80NM — easily saturated in weak fields; it is in demand in radio electronics;
- 81NMA — the best choice for weak fields due to maximum magnetic permeability;
- 27KH — material with a high Curie point (950°C), suitable for use in high-temperature conditions;
- 49K2FA-VI — magnetic saturation up to 2.35 T and high magnetostriction, ideal for powerful generators.
Ours steels and alloys provide stable characteristics and meet the most stringent requirements of modern industry. Contact usto discuss your needs and find optimal solution for your project. PZPS is the guaranteed success of your developments!
