Induction Brazing
Is the joining of two metals (similar and dissimilar) to form a strong and leak proof joint. With induction, the process can be done rapidly and inexpensively. The process with induction can be automated and is easily repeatable part after part. With an induction brazing system, the operation is as simple as pushing a button and the power and heat cycle time are perfectly controlled. SCROLL TO THE BOTTOM OF THE PAGE FOR VIDEOS THAT COMPARE INDUCTION BRAZING WITH TORCH BRAZING.
Brazing is defined as melting the braze filler material above 840 degrees F (450 C). A properly brazed joint will be stronger than the base metals being joined.
The filler metal will bond to the base metals producing a very strong joint. The filler metal melts at a lower temperature than the base metals and flows by capillary action through the entire joint.
Proper procedures must be followed to ensure a good joint, no matter the metals you're wanting to braze:
- Clearance: .001 to .003 and not more than .005.
Coefficients of expansion must be considered when joining different base metals.
- All parts must be cleaned and free of dirt, oil and grease prior to assembly. Parts should be brazed asap so they won't become re-contaminated.
- Brazing Flux: Brazing flux is used to prevent oxides from forming while the parts are being heated. Brazing flux absorbs oxides and helps the flow of the filler metal. Contrary to belief, flux does not clean the parts and is not a substitute for the cleaning procedure. Some alloy manufacturers offer brazing materials with flux already in it, eliminating the need for the second step of adding flux to your brazing material. Separate brazing flux can come as pre-formed rings or as an injectable paste.
- Assembly: Aligning and supporting the parts to be brazed. Insertion should be 3T.
- Brazing the parts: Heat the base metals evenly so the metals will allow the filler metal to wet evenly on both surfaces.
- Cleaning the joint: Getting rid of the flux residue can be done with a hot water wash and brushing. If necessary a wire brush can be used.
These are a few of the basic rules for brazing. Choosing filler metals and brazing in atmospheres can be a complicated issue. Please feel free to contact us at (949) 232-5837 or Sales1@Inductronix.com with your brazing questions and problems and we will try to assist you.
Brazing Various Metals
Brazing Aluminum: The brazing of aluminum is tricky business, as the temperature for brazing aluminum is very close to its melting point. Selecting the right power supply kW and profiling the load coil requirement, as well as accurate temperature control, are critical to ensuring a strong bond without melting any part of the workpiece. We typically recommend an induction machine in the 2-20kW range for brazing aluminum. We can work with you in determining your exact requirements, and can run tests on your parts at our test lab located in Southern California.
Brazing Copper: Copper is more difficult to heat than magnetic steel. We typically recommend an induction machine in the 2-20kW range for brazing copper. We can work with you in determining your exact requirements, and can run tests on your parts at our test lab located in Southern California.
Brazing Silver: Silver brazing is more straight-forward than aluminum or copper brazing. A smaller kW induction machine (2 kW) would be suitable for brazing silver for jewelry applications.
Brazing Titanium: Titanium brazing requires a much higher temperature than any of the other alloys discussed, but over-heating can affect the hardness of the material. An exact temperature measuring device is critical, preferably a non-contact optical pyrometer. We recommend a non-contact method of heating with automatic emissivity control in the 2-20kW range for brazing Titanium. We can work with you in determining your exact requirements, and can run tests on your parts at our test lab located in Southern California.
Brazing Steel: Some steel is magnetic and some non-magnetic, and that affects the size of the power supply needed for the induction brazing of steel. We typically recommend an induction machine in the 2-20kW range for brazing steel . We can work with you in determining your exact requirements, and can run tests on your parts at our test lab located in Southern California.
Brazing Brass: Brass is non-magnetic, and is a softer material than steel or Titanium. Care must be taken not to melt the brass before brazing can take place. We typically recommend an induction machine in the 2-20kW range for brazing brass . We can work with you in determining your exact requirements, and can run tests on your parts at our test lab located in Southern California.
Please contact us at (949) 232-5837 or Sales1@Inductronix.com to discuss your particular brazing requirements.
