Induction Heating FAQs, Tips, and Recommendations
What is induction heating?
Induction heating is a non-contact process that uses high-frequency electromagnetic fields to generate heat directly inside an electrically conductive material. Other heating methods rely on external flames to transfer energy inward, but induction heating makes the target material generate its own heat internally.
You can read more about induction heating from the experts at Radyne.
How does induction heating work?
Induction heating works through alternating current flows through a copper coil, where the current changes direction thousands of times per second (high-frequency AC). The coil creates a changing magnetic field which extends around the coil. A metal object is then placed inside or near the coil, and the changing magnetic field induces electrical currents (eddy currents) inside the metal.
Learn more about inductor design and eddy currents from Radyne.
What metals can be induction heated?
Most electrically conductive metals can be induction heated, although some heat more efficiently than others depending on their electrical resistance and magnetic properties. Ferromagnetic metals are excellent options for induction heating, and these include carbon steel, alloy steel, stainless steel, cast iron, nickel, and some cobalt alloys.
Read more about induction melting and casting of metals.
Does induction heating work on aluminum?
Yes, industrial heating processes use aluminum in induction heating. However, aluminum is not ferromagnetic, so it does not benefit from magnetic hysteresis heating. Instead, it heats solely through eddy currents induced by the alternating magnetic field.
Read more here about aluminum induction brazing advantages.
Is induction heating more efficient than gas heating?
Yes, in most industrial applications, induction heating is more efficient than gas heating. It’s more efficient in multiple ways, as shown in this table:
| Energy efficiency | Typically 70–95% of electrical energy reaches the part in induction heating | Gas heating is often 20–60% overall, depending on furnace design and losses |
| Heat-up time | Seconds to minutes for induction | Minutes to hours for gas |
| Temperature control | Very precise for induction | Less precise, especially for localized heating for gas |
| Heat location | Only the desired area for induction | Entire furnace or surrounding area for gas |
| Scale and oxidation | Minimal for induction | Greater oxidation and scale formation for gas |
| Emissions | No on-site combustion for induction | Gas produces combustion gases and CO₂ |
What industries use induction heating?
People use induction heating across many industries, including Manufacturing, Automotive & Transportation, Aerospace, Defense, HVAC-R, Medical, Packaging, Consumer Goods, and more.
Radyne builds induction heating equipment for a wide range of industries throughout North America. Contact us today to learn more about our equipment.
Is induction heating safe?
Yes, induction heating is considered one of the safest industrial heating methods available. Heat is created directly inside the conductive target rather than on the heating surface or through an open flame, meaning it eliminates many of the most common thermal and chemical hazards.
Learn more about induction heating safety from Radyne.
What is an induction coil?
An induction coil is the component of an induction heating system that creates the alternating magnetic field used to heat a metal workpiece. The coil acts as the “tool” that transfers electrical energy into the metal through electromagnetic induction.
The induction coil is one of the most important factors in an induction heating system. A well-designed coil determines:
- Heating speed
- Temperature uniformity
- Energy efficiency
- Heating depth
- Repeatability
- Overall process quality
Read more about induction coils and tooling from Radyne.
What water should I use for cooling my induction equipment?
For closed-loop cooling systems, the most suitable coolant is usually distilled water. This specially treated water does not contain any impurities or minerals present in tap water. This helps minimize the risk of corrosion and scale formation within the cooling system.
Using distilled water helps prevent the buildup of mineral deposits, which can impede heat transfer and reduce the cooling system’s efficiency. It also reduces the likelihood of corrosion, which can damage components over time.
It’s important to note that using tap water or other water with high mineral content in a copper-based cooling system can lead to various issues, including scale formation, corrosion, and reduced performance. Therefore, it is generally recommended to use distilled water for optimal operation and longevity of the system.
In certain cases, other types of purified water such as deionized water, RO (reverse osmosis) water, and demineralized water can also be suitable coolants. However, Radyne does not recommend their use if your cooling system contains stainless steel components. This is because there is evidence to suggest that these types of water, especially deionized water, can speed up the corrosion of stainless steel.