Induction heating is a precise method using alternating magnetic fields to induce electric currents in the material generating heat.
The equipment used for this process is typically called an induction heating system. These systems are integrated solutions consisting of a generator, an inductor, and a control system. While the “generator” provides the power, the “induction heating system” represents the entire functional assembly used in industrial applications like welding, brazing, and thermal processing.
In this article, we explain how induction heating works, present the induction heating system developed and designed by SEIT Elettronica, and their advantages for production lines that require precision, stable results, and integration with automated systems.
Induction heating systems: What are they for and how do they work?
Induction heating is based on the generation of a variable electromagnetic field that, interacting with the conductive material, generates induced electric currents (parasitic currents known as Foucault currents) within it. These currents, circulating in the material, encounter an electrical resistance that produces heat directly in the workpiece through the Joule effect, without the need for contact with an external source.
The generator, which, as mentioned, is the energy source for the induction heating system, in turn powers an inductor, a conductive coil designed based on the geometry of the component being heated and the specific area on which the heating must be concentrated, such as a joint to be brazed or an area to be soldered.
The shape, size and position of the inductor determine the distribution of the electromagnetic field and therefore the localization of the energy transferred to the workpiece.
Induced currents generate heat within the material in a controlled and targeted manner. This allows for localized heating, minimizing thermal dispersion and limiting the process strictly to the required areas. The result is improved dimensional stability and a reduction in undesirable metallurgical alterations. This is particularly effective when processing heat-sensitive materials such as copper and high-conductivity alloys, as well as brass, bronze, and stainless steel.
How induction heating works
An induction heating system is composed of three main elements: generator, inductor and control system.
- The generator defines power and frequency, regulating the transferred energy and adapting it to the type of processing required. The generator supplies the power required for the process and works at a frequency that automatically adapts to the connected inductor, within a pre-established range, ensuring maximum energy transfer efficiency depending on the type of processing.
- The inductor determines the distribution of the magnetic field, depending on the geometry of the piece and the area to be treated, concentrating the heating where necessary.
- The control system manages cycle times, operating sequences and processing parameters, ensuring process repeatability and stability of results over time
Frequency directly affects the depth of heat penetration (the so-called “skin effect”).
To clarify the concept: high frequencies concentrate energy on the surface layers of the material. High-frequency generators (typically ranging from 150 to 400 kHz) are therefore used for precision work on small components. Conversely, lower frequencies (below 50 kHz) allow heat to be distributed across greater thicknesses, making them more suitable for larger or high-volume components that require deep, through-heating
Induction heating is applied to electrically conductive materials, with performance varying based on their conductivity and magnetic properties. It is specifically used in the welding and brazing of metals such as copper, brass, stainless steel, and various alloys.
In this context, inductor design plays a key role: the shape of the coil, the distance from the workpiece, and the magnetic field configuration determine the quality of the result. Analyzing the inductor’s characteristics allows the process to be adapted to components with different geometries or to tasks requiring localized intervention, all while maintaining precise control over the parameters.
Advantages of the induction heating process
The use of induction heaters allows for a series of operational advantages, particularly related to process precision and energy and consumption control:
- High thermal precision: Heat is generated only in the target area, reducing deformations and residual stresses.
- Reduced cycle time: Heating is rapid and direct, with significantly shorter heat-to-temperature times than traditional methods
- Energy efficiency: Energy is transferred directly to the workpiece with an efficiency of over 90%, reducing consumption compared to traditional heating systems.”
- Process repeatability: the set parameters remain constant even on continuous production runs.
SEIT Elettronica’s technologies, which we’ll discuss in the next section, also allow generators to be integrated into automated production platforms for brazing, welding, and heat treatment processes.
Induction heating is therefore suitable for industrial processes where parameter control must remain stable over time. For this reason, it finds application in a variety of sectors, each with specific operational needs.
Industrial applications of induction heating systems
Induction heating is used particularly in processes that require temperature control and consistent quality.
One of the most important aspects of this process is the ability to work on specific areas of the component while maintaining the characteristics of the rest of the piece. This approach helps avoid deformations, reduce waste, improve the reliability of joints, and ensure repeatability, especially in serial, high-volume production or on automated lines.
Controlled heat management also allows for the processing of sensitive materials or components with tight tolerances, where even minimal variations can affect the final result. Let’s look at some of the most common technical applications.
Eletronics sector
In the electronics industry, temperature control is crucial to avoid damage to components and ensure the quality of electrical connections, often made on small elements.
Tinning wires to connectors, for example, allows for stable electrical connections, reducing defects related to uneven heating and improving contact quality. Localized heating prevents overheating of insulating materials and ensures long-term electrical continuity. Controlled temperature management allows for uniform melting of the alloy, promoting even wetting and reducing process variability on serial production runs. This improves joint reliability and reduces process variability on serial production runs.
Sensor tinning, another common application, allows for working on sensitive components while maintaining precise temperature control, preventing damage to internal components and preserving functional characteristics and performance reliability. The process can be adjusted based on the component’s volume, alloy type, and inductor geometry, ensuring repeatable results even on very small geometries.
HVAC sector
In the HVAC sector, brazing processes must ensure sealing, mechanical resistance and continuity of heat flow, often on components made of copper, brass or aluminum alloys.
Valve brazing allows for reliable joints on copper, brass, and stainless steel components subjected to continuous pressure and thermal cycles. Localized heating allows for the welding to be performed exclusively on the joint area, preserving the functional characteristics of the valve and adjacent materials. Controlled parameter management ensures process repeatability even on serial production runs, reducing waste and maintaining consistent joint quality over time.
Brazing HVAC manifolds ensures uniform and reliable joints, improving the system’s seal over time. Controlled heating prevents defects such as porosity or failure of the filler material to wettability in the joint areas. Uniform heat distribution also allows for proper diffusion of the filler material, ensuring joint quality even in multi-connection configurations.
Brazing the U-bends on heat exchangers optimizes heat transfer and connection continuity. Controlled heating maintains the quality of the joints even on complex geometries. Adjusting the parameters allows for effective management of thermal mass variations, preventing deformations and ensuring effective sealing over time.
Brazed tool sector
In the toolmaking sector, induction heating is used to create stable couplings between materials with different properties, maintaining precision and durability over time.
Brazing metal inserts onto woodworking bits ensures a stable fit, increasing tool life and maintaining consistent cutting performance. Thermal control prevents deformation and helps the insert adhere properly. Careful management of the thermal cycle also preserves the mechanical properties of the materials involved, improving the tool’s wear resistance and operational stability.
In the toolmaking industry, induction heating is used for brazing carbide or diamond inserts on cutting tools such as wood drill bits, milling cutters, circular saws, and hole saws. The process creates reliable joints between the insert and the steel tool body, precisely managing the thermal cycle to prevent thermal stress cracks caused by the difference in expansion between the materials involved.
Accurate temperature control preserves the insert’s mechanical properties and ensures proper adhesion of the filler material, improving wear resistance and the tool’s operating life. The repeatability of the process makes this technology particularly suitable for serial production, where consistent joint quality is crucial to the tool’s final performance.
Medical sector
The medical sector requires precise, repeatable processes with rigorous parameter control, in line with the high quality standards of the industry.
Brazing brass pins on biopsy needles, for example, creates precise and repeatable assemblies, with accurate parameter control and stable process management even for high production volumes. Localized heating allows for work without compromising the characteristics of the medical device. The ability to set controlled cycles allows for compliance with stringent quality requirements, reducing waste and ensuring uniformity between produced parts.
The applications we’ve just described demonstrate how the principle of induction heating can be applied differently depending on the industry, while maintaining the same control, repeatability, and quality requirements.
To achieve these results consistently, a system capable of precisely managing power, frequency, and operating parameters is needed. This is where induction generators come in, as they form the heart of the heating system and determine its operational performance.
Induction generators in the heating process: the Platinum line from SEIT Elettronica
In the induction heating systems, the generator is the element that ensures stable and controlled results over time.
In this context, the induction generator defines the system’s performance regarding stability, precision, and process parameter management—especially within automated lines, where every variation must be strictly controlled
Platinum Generatro HF & MF
The Platinum line solutions answer to these needs, allowing the system to be configured according to the application and the type of component.
- Platinum HF: high-frequency generator designed for precision heating of small components. It enables localized heating with reduced cycle times and accurate control of the treated area. It is suitable for processes such as tinning and micro-brazing.
Thanks to its high frequency and stable output, it allows energy to be concentrated in very small areas, reducing thermal impact on adjacent areas and improving the quality of joints on sensitive components. Fine power adjustment and automatic frequency adjustment to the inductor allow the process to be optimized based on the required machining operation. - Platinum MF: medium-frequency generator suitable for thicker components or joints requiring greater heating depth. It is used in brazing applications and more complex thermal assemblies.
The greater heat penetration depth allows for more uniform heating over large cross-sections, ensuring joint continuity and process stability even in the presence of high thermal masses. Here too, parameter control allows for energy adjustment based on the component and the required process.
Alongside the generators, the Platinum TT and Platinum HUB work platforms allow the process to be integrated into production lines. These technologies enable the coordinated management of all processing stages, integrating Platinum series generators—with power outputs ranging from 2.5 kW to 25 kW—into a single platform, providing companies with tailored solutions based on their specific production cycles.
Program management, parameter control, and automation of operational sequences maintain consistent quality even during continuous production. This way, the process isn’t limited to a single operation, but becomes part of a structured production system.
Want to improve the efficiency of your induction heating processes or integrate automated, customized solutions into your production line? The SEIT Elettronica team is available to offer the solution best suited to your operational needs: Contact us Now
