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 a brazing system the operation is pushing a button and the power and heat cycle time are controlled for a perfect joint every time.
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.
- 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.
- Fluxing the parts: Flux is used to prevent oxides from forming while the parts are being heated. 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.
- 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 with your brazing questions and problems and we will try to assist you.
