Induction applications & consulting

A flame heats everything it touches. A furnace heats the whole part and takes its time doing so. Neither is practical when only one zone needs to get hot, the part moves on at cycle rate, and the heat input has to be the same from piece to piece. Induction heating puts the heat where it is needed, without contact and repeatably. H. Sigrist & Partner AG supplies the system: generator, inductor and, where wanted, the temperature control.

Induction Heating in Detail

An alternating current creates a magnetic field. That field induces eddy currents in the conductive workpiece, which heat the part directly. The heat is generated inside the component rather than transferred from outside, so the heating system itself stays largely cool. With ferromagnetic materials a second effect is added: a large share of the heat comes from magnetic reversal losses. This is why steel and other ferromagnetic materials respond particularly well to induction. What that means in operation:

Heating is confined to one zone, the rest of the component stays cold
No contact between heating system and workpiece, so no wear at a contact point
No exhaust gas, which makes it usable where an open flame is ruled out
Heat input is set through power and time and is therefore reproducible from part to part

Hardening

Raising the surface hardness of metal parts. The surface layer reaches austenitising temperature while the core stays comparatively cool.

Tempering and soft annealing

Changing material properties through controlled heating and cooling.

Soldering and brazing

Heating to the melting temperature of the filler metal for metallic joints. The heat can be confined to the joint, leaving adjacent components unaffected.

Forming

Heating the workpiece to process temperature to improve formability.

Generator

Supplies the energy. Its power rating is matched to the workpiece and the heating process.

Inductor

Delivers the energy into the workpiece as a magnetic field. The inductor is a coil with cooling water flowing through it, designed around the intended heat input and the geometry of the part. It is the component that decides most about the result.

Temperature control

Optional. A controller with suitable sensors holds the temperature stable across the process instead of merely setting a time.

The energy demand of an induction heating process follows from the interplay of material, frequency range and power. These three have to be matched to each other, otherwise the part either fails to reach temperature or gets hot in the wrong place. Electrically conductive and ferromagnetic materials can be heated. That includes steel and stainless steel as well as aluminium and brass. Non-conductive materials are ruled out, and with highly conductive, non-ferromagnetic materials such as aluminium the effort is higher than with steel.

For induction technology we work with CEIA. We take on the design for your process, the selection of generator and inductor, and commissioning on site. The process is not the right choice for every task. With very large parts, with materials whose electrical properties work against them, or at quantities that do not justify building an inductor, we say so. An inductor is built for one geometry, and that decision should be right before procurement rather than after.

Application Examples

Continuous induction annealing of a chain

Soldering RF connectors with automatic solder wire feeding

Soldering application with solder paste dispensing in electronics manufacturing

Induction brazing of carbide tips onto a saw blade

Induction heating of a workpiece for a forming process

Heating head with induction coils for sealing plastic containers

Discuss Your Application

For an initial assessment, five pieces of information are sufficient:

the material
the geometry and mass of the workpiece
the target temperature
the zone to be heated
the required cycle time

This allows us to assess the required generator power and how the inductor needs to be designed.

Let's optimize your manufacturing processes together!

Get in touch with us to discover how our solutions can help improve your production processes.
We’re looking forward to discussing your requirements and finding the right solution for you.