Induction Heating Applications Overview
Induction heating is used for an ever-widening range of industrial and scientific applications: material joining processes such as brazing, soldering and curing; material processing applications including hardening, annealing and melting; and component assembly applications such as epoxy bonding and heat staking metal into plastic. Our engineers have also applied the technology for catheter tipping, hot heading and other component manufacturing processes.
In our Applications Laboratory, we are always evaluating new uses for induction heating by evaluating part samples and analyzing process requirements submitted by our customers. Following is a summary of the induction heating applications we encounter most frequently and direct links to many of the lab reports prepared by our engineers.
Brazing
Brazing is the process of joining two or more pieces of metal or ceramic material with a molten filler metal such as silver, aluminum alloy or copper. Brazing requires a higher temperature than soldering but produces a very strong bond which withstands shock, vibration and temperature change. Brazed joints are both liquid- and gas-tight and provide good electrical conductivity.
An induction brazing system quickly delivers highly localized heat to minimize part warpage and distortion. Brazing in a controlled vacuum or in an inert protective atmosphere can significantly improve overall part quality and eliminate costly part cleaning procedures.
Please visit The Brazing Guide section of our website for in-depth information about brazing processes, materials, filler metals and equipment. Following are four examples from our Applications Research Database which show how induction heating has been successfully used for brazing different metals and materials.
Heat Treating
Heat Treatingis the controlled heating and cooling of a metal or alloy to change its metallurgical properties while maintaining its shape. Though most often a planned and controlled manufacturing process, heat treating is sometimes the undesired result of welding, hot forming or other manufacturing processes which heat or cool the material. The most common heat treating process is hardening, in which the metal is heated to increase its strength. But metals can also be heated to restore ductility, remove residual stress and improve machinability. Steel parts are particularly well suited for heat treating. Hardening, Annealing, Tempering, and Stress Relieving are common heat treating applications.
The hardening process generally improves the metal's strength and wearability. Many types of steel can be directly hardened provided they have sufficient carbon and alloy content. A key step in the hardening process is rapid quenching or cooling of the metal once it has reached the desired temperature. Often accomplished with a water bath, the rapid quenching step preserves the increased strength within the metal.
Annealing and tempering processes are used to soften metal for improved ductility and machinability, as well as to relieve residual stress. In contrast to hardening, annealing involves a much slower heating step followed by gradual cooling of the metal. Tempering refers to a reheating and slow cooling of metal which has become too brittle as a result of a hardening process.
Melting
Hard metals can be melted with an induction heating furnace. The metal is placed on a non-conductive crucible; when induction heating power is applied, the eddy currents circulating within the metal effectively stir the molten mass as it melts. Very high quality, uniform melting can be achieved with precious metals, high quality steels and non-ferrous alloys for casting procedures. metals with solid state RF induction heating is usually accomplished by heating the metal in a crucible made from a non-conductive refractory material. The charge of metal within the crucible is melted down to liquid form.
Shrink Fitting / Heat Staking
When one piece of metal is designed to be inserted into a second piece, induction heating can be used to "shrink fit" the two pieces together. The first or larger piece containing the opening is heated to expand the size of the hole. The second piece is then inserted into the opening, and as the first piece cools and shrinks back to its original size, the resulting pressure holds the two pieces together in a strong bond. A press-fitting procedure applies a physical force during the cooling process to make the bond even stronger or shorten the cycle time.
Pre-Heating
Induction heating can be used very effectively to preheat conductive materials for forging, welding, hot forming and hot heading. For example, the tips of turbine engine blades can be placed in a specially designed induction coil and heated to the desired temperature for welding repairs. The process is easily handled in an atmospheric glove box filled with argon or other inert gases. The induction preheating step improves cycle time and reduces stress on the rest of the blade.
General Purpose Heating
Induction Heating is also well suited for many other types of applications:
• Bonding
• Glass to Metal Sealing
• Metal-to-Plastic Insertion
• Soldering
• Crystal Pulling
• Material Testing
• Thread Rolling
• MOCVD
• Drying/Curing
• Outgassing
• Wire Tinning
• Sintering
Send Us Your Parts For A Free Evaluation
Would induction heating be applicable to your heating process? Our advanced technology often proves to be the best and most profitable alternative for a wide variety of industrial heating applications. We invite you to send us your sample parts and process description for a free evaluation and system recommendation.
Why not find out if a customized induction heating solution is right for you? For more information, visit our Parts Evaluation page or send us an e-mail using the link below. We look forward to hearing from you!