Magnetic Flux Concentrators

Alternating current in an induction coil generates a magnetic field in the coil called magnetic flux. When you place a metallic workpiece into the flux, it creates eddy currents that flow through the metal. Electrical resistance converts the currents into heat.

Magnetic flux, electrical conductivity, and magnetic properties determine the amount of heat produced. We use magnetic flux concentrators to increase the desirable properties of induction heating coils and improve their efficiency.

Field concentrator coils are regular induction coils that have added ferrites or silicon steel laminations. They work to focus and intensify the magnetic flux field (and therefore heat) onto a specific area of the workpiece, targeting heat exactly where it’s needed and shielding the other parts of the workpiece. In the picture above, the Concentrators are the silver rectangular “teeth” in the coil on the right.

Common materials for flux concentrators include ferrites or silicon steel. Each has properties that could make it a good choice for an induction heating system.  

1. Ferrites

We frequently use a ceramic-like material called ferrite for field concentrators. Depending on their composition, we either machine them or mold them into the desired shapes.

2. Silicon Steel Laminations

With a long history of use in induction heating coil systems, silicon steel laminations are ideal for applications with high heat loads. They are very durable and have a high saturation flux density.   

3. Soft Magnetic Concentrators

Easy to mold and shape, soft magnetic concentrators install quickly onto coils. They are particularly effective for applications targeting a small area, such as a specific crankshaft component or RF connectors. Soft magnetic concentrators are a low-cost solution that can significantly improve heating efficiency.   

Induction Technology Solutions engineers have a wealth of knowledge and experience in the induction heating industry. We can design custom magnetic flux concentrators for induction heating systems that optimize processes and improve efficiency. Request a quote today.