Steels and alloys in electrical engineering and electronics: types, properties, and characteristics

Modern technologies require specialty steels and high-quality alloys that ensure durability, reliability, and efficient operation of electrical and electronic devices. These materials are used in a wide range of fields — from household appliances to complex industrial systems.

In electrical engineering they are used in transformers, generators, and electric motors, substantially reducing energy losses and improving equipment efficiency.

In electronics they are needed for manufacturing instrument enclosures, printed circuit boards, cooling heat sinks, and other components where thermal conductivity, wear resistance, and stability under temperature service conditions are important.

Key properties 

For effective use of metals in electrical engineering and electronics, their key physical and mechanical properties must be taken into account:

• Electrical resistivity — determines a material’s ability to conduct current. For conductors (for example, copper or aluminum) low resistivity is important, whereas resistors require materials with high electrical resistivity.
• Thermal conductivity — determines a material’s ability to remove heat. High thermal conductivity is important for cooling heat sinks, processors, power transistors, and transformers. Copper and silver alloys have high thermal conductivity, whereas insulating materials have low conductivity.
• Magnetic properties — include magnetic permeability, coercive force, and hysteresis losses. These properties are especially important for transformers, relays, and electric motors. For example, to minimize losses caused by magnetization and demagnetization, specialty silicon steels are used in transformer cores.
• Strength and wear resistance — mechanical strength, hardness, and vibration resistance are important for components subjected to significant mechanical loads, for example in rotor systems of electric motors or in moving parts of generators.
• Thermal stability and thermal expansion coefficient — especially important for high-temperature devices such as thermal sensors or heating elements. For example, Invar (an alloy with a low linear expansion coefficient) is used in structures where even minimal thermal deformation is unacceptable.

Selecting a material with optimal physical characteristics for a specific electronic application makes it possible to ensure high performance, reliability, and longevity of components.

Electrical steels

Specialty materials that occupy a central place in the manufacture of various electronic and electrical devices that convert and transmit electrical energy. These steels have special magnetic properties that make it possible to reduce energy losses and raise the efficiency of electric motors, amplifiers, relays, and other equipment.

Main properties

High magnetic permeability

Electrical steels can magnetize and demagnetize easily, which enables them to transmit and convert electrical energy efficiently.

Low hysteresis losses

In each cycle of magnetization and demagnetization, part of the magnetic energy is lost through eddy currents. Electrical steels have low hysteresis losses, which reduces heating and improves core efficiency in both forward and reverse operation.

Low coercive force

Demagnetizing materials requires an external magnetic field. The higher a material’s resistance to such influence, the harder it is to change its magnetic induction. Electrical steels have low coercive force, which facilitates magnetization and demagnetization.

Isotropic characteristics

Electrical steels should have the same properties in all directions to ensure uniform distribution of the magnetic field.

Types of electrical steels

Depending on chemical composition and processing method, electrical steels may belong to one of the following types:

• Transformer steels. Contain 2–4% silicon, giving them high magnetic properties and low eddy-current losses. Used in transformer cores for transmitting electrical energy.
• Relay steels. Used in contactors and relays for controlling electrical circuits. High saturation magnetic induction and low coercive force are important for them.
• Alloys for magnetic amplifiers. Used to amplify weak electrical signals. They must have high magnetic properties and a low noise level.
• Dynamo steels. Used in rotating and stationary parts of generators and motors to convert mechanical energy into electrical energy and vice versa. They combine high strength with good magnetic permeability.

Soft magnetic and hard magnetic materials

Soft magnetic alloys

These materials magnetize and demagnetize easily. They have high magnetic permeability and low hysteresis losses, which makes them ideal for devices where efficient conversion of electrical energy into magnetic energy and vice versa is required. Examples of soft magnetic materials are iron–nickel and iron–cobalt alloys.

Application areas:

• Transformers. Used to transmit electrical energy and provide efficient conversion of voltage and current.
• Electric motors and generators. Convert electrical energy into mechanical energy and vice versa, allowing motors to rotate and generators to produce electricity.

Hard magnetic alloys

They have high coercive force and residual induction, meaning they can retain magnetization even after removal of an external magnetic field. They are used when magnetization must be retained for a long time, for example in the manufacture of permanent magnets.

Application areas:

• Permanent magnets. The alloys retain magnetization for a long time, which makes it possible to use them to manufacture permanent magnets. They are used in electric motors, generators, magnetic levitation systems, and other devices.
• Data storage. A number of hard magnetic materials are used as information carriers in some types of data-storage devices.
• Sensors. Materials that are poorly affected by an external magnetic field are often used in sensors for determining position, speed, and direction of motion.

Alloys with high electrical resistivity

Materials with high electrical resistivity are characterized by property stability under changing temperature and other conditions. They are used in electronics and electrical equipment where electrical parameters must be controlled precisely.

Application examples:

• Heating elements — provide uniform heating and precise temperature control. This is especially important in fields such as medicine, industry, and scientific research.
• Resistors — used for precise control of electrical resistance. This makes it possible to create resistors with given characteristics, which is necessary for developing modern electronic circuits.
• Resistance thermometers — sensitive elements that respond to temperature changes are made from precision alloys. Property stability makes it possible to obtain accurate measurements regardless of service conditions.
• Pressure sensors — precision alloys can be used to manufacture components that convert mechanical pressure into an electrical signal. High accuracy and stability of the materials ensure reliable sensor operation.

PZPS produces a number of materials with high electrical resistivity, including alloys of grades Kh20N80 and Kh15N60. You can buy cold-rolled nichrome strip from us manufactured to GOST 12766.2-90 as well as to customer specifications.  

Precision alloys with a controlled CTE

Materials with a controlled thermal expansion coefficient have special properties, including characteristic stability under significant changes in service temperature conditions. They are used in various areas of electrical engineering and electronics where precise control of temperature parameters is required.

In microelectronic devices such as integrated circuits and microchips, components made from precision alloys withstand high temperatures without deformation or dimensional change. This ensures accuracy and reliability of device operation. For example, Invar (36N) is widely used in microelectronics and precision optical instruments where resistance to deformation is important.

Precision alloys produced by PZPS

At PZPS you can buy:

• cold-rolled strip and sheet of electrical steel;
• semi-finished products and strip of soft magnetic (27KX, 50NP, 80NM and others) and hard magnetic materials (EP-298, 13NKhM);
• precision alloys with high electrical resistivity and materials with a controlled CTE.

Our enterprise also offers manufacture of steels and alloys to individual customer requirements. All products meet modern quality standards and undergo strict control at every production stage. Contact us for advice and to place an order. Our specialists will help select the optimal solution for your project and answer your questions in detail.

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