Brazing is a process in which a filler metal is melted and flowed into a joint to connect two or more metal items at a high temperature. Brazing differs from welding in that brazing does not involve melting of the pieces being connected. Brazing differs from soldering in that soldering is performed at a lower temperature.

In the past, brazing projects were completed either by using a hand-held torch, which required a very skilled worker with a steady hand, or in large batches using a furnace.  Today, induction brazing, a precise process that heats only the braze points and the brazing alloy, is a faster, safer and more efficient method – especially if your shop produces in large volumes and incorporates a level of automation.  That said, manufacturing outfits that braze in smaller quantities can also benefit from induction brazing thanks in part to a handy tool called a brazing pistol.  Brazing pistols are pneumatic tools designed to safely grip the workpiece as well as hold the induction coil during the brazing process.  These tools can be customized for your part and along with custom-designed inductors and a power supply from eldec to make the brazing job much easier.  Continue reading to learn more about the benefits of induction brazing as well as how eldec’s experience and induction heating equipment can improve your brazing process.

Table of Contents

We’ve organized this lengthy article into sections.  Feel free to click ahead to an area that interests you or just dive in.

• Induction brazing systems and processes
• Common applications for induction brazing
• Induction heating benefits for brazing
• Examples of induction brazing
• Generators and inductors for induction brazing

Induction brazing systems and processes

Precisely controlled, powerful generators from eldec provide fast and accurate heating, ensuring that your production process can enjoy these benefits. Whether your workpieces are large, medium or small, in the plant or in the field, eldec makes an induction brazing generator to meet your specific needs. Each system is manufactured to improve your part quality as well as increase the speed and efficiency of your manufacturing process. eldec manufactures several categories of induction heating generators for a wide variety of processes and applications. They are easy to setup and use.  They all come with:

• A simple and intuitive screen for all generator commands, including heating modes (continuous, tap and timer) and heating times/powers.
• An auto-adjustment of frequency based on induction coil and work part self-tuning. eldec’s power supplies (generators) feature fixed power programming and automatic variable frequency (not fixed frequency), which means that they can operate at different frequencies within a specific range, with equal power and precision, without resetting switches or capacitor banks.
• Handheld coax output transformers for flexible setup.
• The ability to remove and replace inductor coils very quickly — often in less than two minutes — allowing switching between processes and applications.

Many are also easily integrated into larger system cells via optional interface modules, such as Profibus, Profinet or Ethernet IP.

eldec offers solutions for induction brazing workpieces with the following materials:

• Copper and copper alloys
• Brass
• Aluminum
• Iron
• Steel, stainless steel and all types of carbides
• Tungsten
• Chromium
• Nickel and nickel alloys
• Cobalt and precious metals
• Dissimilar metal brazing applications

Common applications for induction brazing

New applications for induction brazing are discovered every day, but here is a list of common induction brazing applications:

• Brazing copper heat exchanger tubes in refrigeration units and custom trucks
• Strand brazing flat copper wire and squirrel cage rotors used in motor and transformer manufacturing
• Brazing bus bars
• Brazing brass screw fittings in a diverse range of piping systems
• Brazing carbide pins used in road construction
• Carbide blade manufacturing
• Steel tube assembly
• Large motor and transformer repair for things like wind turbines, hydro-electric turbines, nuclear power transformers, mining equipment and farming equipment
• Electric and hybrid vehicle manufacturing
• Medical device manufacturing

Induction heating benefits for brazing

Induction brazing has many advantages over flame or furnace brazing. This short list may make you reconsider your current manufacturing process:

1. Speed up production
2. Braze more precisely
3. Create superior joints with consistent heat
4. Easily setup a reproducible process
5. Increase energy efficiency and lower utility costs
6. Improve worker safety
7. Reduce down time
8. Increased equipment reliability

Continue reading to see how other manufacturers were able to use induction brazing in their operations.

Examples of induction brazing

Components like this carbide metal pin, pictured in the photo on the right, are used in road building and in a similar form in mining as cutter heads. In this simple example, carbide metal was brazed to the end of the head of pins to extend their service life. Induction brazing was used due to the large quantity of workpieces, the quality required and to increase energy efficiency. eldec generators are often used in more complex settings with a higher level of automation than shown here.  Follow the links below to read more about other applications and see videos demonstrating each process.

Brazing flat copper wire

The joints of stacked, flat copper wires – like those often used in many and various types of electrical machine manufacturing – are easy to braze with a handheld, coaxial transformer mounted on a pneumatic brazing pistol attached to the generator via a cable output of up to 15 meters long (49 ft).

Brazing flat copper parts

Brazing short-circuit rings

Having the ability to braze all of the rotor bars on one end of a squirrel cage rotor for an electric motor at one time without ring distortion is a remarkable achievement made possible by using induction heating.  The savings in production time are made even sweeter by the consistency and precision you’ll see in brazes.

Brazing heat exchanger tubes

Using induction brazing rather than a conventional torch can increase the quality of joints and shorten the time necessary for each braze; however, the ease of creating a reproducible process makes induction brazing ideal for serial, high volume production processes such as induction brazing of heat exchangers.

Brazing in an inert atmosphere

Braze without messy flux! Watch the video to see how inert atmosphere brazing works. Induction brazing in an inert atmosphere is a great way to create high quality brazed joints while speeding up production.

High power brazing

It can be difficult to control the temperature in a specific section of a workpiece while brazing with a torch – especially when brazing large parts. This case study explains how brazing using high power induction can connect large parts with strong joints that will last.

Generators and inductors for induction brazing

eldec offers a wide array of generators for induction brazing. Whether your parts are large or small, simple or complex, eldec can custom manufacture an induction brazing system to match your workpiece as well as you specific manufacturing environment.  Follow the links below to learn more about each of our lines of induction brazing equipment.

• eldec PICO generators – This line includes generators that are available in medium and high frequencies, are easy to operate and are suitable for a wide range of induction brazing applications.  The PICO-S, in particular, is compact, portable and affordable.  Models start at $17,500.
• eldec MiniMICO – A mobile, medium frequency, induction power supply that can be configured for induction brazing and die hardening works well with optional accessories including a boom arm to support the coax weight and a brazing pistol to reduce operator repetitive stress injuries.
• eldec MICO generators – The MICO series’ innovative design integrates the frequency converter and coolant system in a single housing. Small and compact, stationary or mobile, they are a flexible and practical solution for a wide range of uses.
• eldec ECO LINE – MF generators - Robust and compact, ECO LINE series, medium frequency power supplies have a continuous power rating from 5 to 150 kW. Suitable as a stand-alone generator or for integration into production systems.
• eldec ECO LINE – HF generators – Also robust and compact, these high frequency power supplies have a continuous power rating from 5 to 75 kW and are suitable as a stand-alone generator or for integration into production systems.
• eldec CUSTOM LINE – MF/HF/LF generators - Get the best power supply tailored precisely to fit your specific induction brazing application. Each device can be custom-configured and a huge range of options are available, including single or multiple outputs and a wealth of power and frequency combinations. Models are also available as dual frequency (DF) or simultaneously dual frequency (SDF®).
• eldec CUSTOM LINE – DF generators - eldec’s Dual Frequency Generators (DFG) have two different frequency ranges that you can switch from back and forth. They are ideal for manufacturers who want just one generator but have more than one application that requires different frequency ranges (ie. one medium and one high frequency). With this type of power supply, you can run one operation at one frequency; stop and change the setup; and run another operation at another frequency.

• eldec CUSTOM LINE – SDF® generators - If your manufacturing line requires using two different frequencies on the same workpiece at the same time, our Simultaneous Dual Frequency (SDF®) generators may be what you need. These generators are ideal for gear hardening.

An inductor’s shape and construction style are determined predominantly by the geometry of the workpiece section to be heated, and the possibilities are infinite. The location of the components during the manufacturing process can also determine which type of inductor to use. eldec LLC can help you decide which type of generator and induction coil is best for your parts and operation.

Leading manufacturer of induction heating equipment for your brazing application

Since 1998 eldec LLC has manufactured induction power supplies and induction heating coils in Auburn Hills, Michigan for manufacturers in the United States, Canada and Mexico.  Our skilled technicians and application engineers have years of experience designing and manufacturing customized solutions for specific production applications and parts as well as unique manufacturing environments.  We can custom design a system to match your workpiece – large or small. Our power supplies are rugged and flexible enough to be used in your shop or in the field, in remote locations or tight spots.

eldec offers a complete range of aftermarket services because we know that sharing technical knowledge and hands-on experience is just as important as selling quality equipment and tools.  Our staff will work hard for you – from project concept through design and manufacturing, equipment commissioning, trouble shooting and maintenance as well as employee training.  Our goal is to make your job easier, more cost effective and efficient, and to nurture a long-lasting, mutually beneficial, working relationship

Schedule a consultation

Want to learn how induction brazing can help your operation? Schedule a consultation with our induction heating experts. eldec LLC’s team will help you choose the induction power supply and design induction coils for your specific parts and production environment. If induction heating is new to you and your staff, operator and maintenance training is available in our plant in Auburn Hills, Michigan or at your site. Give us a call or send a request for a consultation and we’ll contact you. We look forward to talking with you.