Brazing flux is a substance used to promote the flow of molten brazing filler metal and to prevent oxidation of the base metal and filler metal during brazing. It is typically a paste or powder that is applied to the joint before brazing. Brazing flux can be either active or inert. Active fluxes react with the base metal and filler metal to form a protective layer that prevents oxidation. Inert fluxes do not react with the base metal or filler metal, but they provide a barrier to oxidation.
Brazing flux is available in a variety of types, each with its own advantages and disadvantages. Some of the most common types of brazing flux include:
- Rosin flux: Rosin flux is a natural product that is derived from tree sap. It is a good all-around flux that is easy to use and produces good results. However, it can be corrosive to some metals and can leave a residue on the joint.
- No-clean flux: No-clean flux is a type of flux that does not require to be cleaned after brazing. This makes it a good choice for applications where cleanliness is important. However, no-clean flux can be more expensive than other types of flux and it may not produce as good of results.
- Activated flux: Activated flux is a type of flux that is activated by heat. This makes it a good choice for applications where the joint will be exposed to high temperatures. Activated flux can be more corrosive than other types of flux and it may leave a residue on the joint.
The type of brazing flux that is best for a particular application will depend on the base metal, filler metal, and the desired results. It is important to consult with a brazing expert to choose the right flux for the job.
Here are some of the benefits of using brazing flux:
- Promotes the flow of molten brazing filler metal.
- Prevents oxidation of the base metal and filler metal during brazing.
- Creates a protective layer on the joint that prevents corrosion.
- Makes brazing easier and faster.
- Improves the quality of the brazed joint.
Here are some of the drawbacks of using brazing flux:
- Can be corrosive to some metals.
- Can leave a residue on the joint.
- May not be suitable for all applications.
Overall, brazing flux is a valuable tool that can be used to improve the quality and performance of brazed joints. It is important to choose the right flux for the job and to follow the manufacturer's instructions to ensure safe and effective use.