Need to join aluminum parts into super strong, leak-proof assembles? This is how brazing aluminum works. Brazing creates incredibly durable bonds without extreme heat or distortion by using a filler metal melted between the aluminum pieces. In this article, we’ll learn everything you need to know about brazing aluminum in no time.
How Brazing Aluminum Works?
Brazing uses a filler metal with a lower melt point than aluminum. When heated, the filler flows smoothly into the joint through capillary action. Then, a tough bond is formed upon cooling. Common aluminum braze fillers contain silicon or zinc which melts between 565-615 degrees Celsius and safely below aluminum’s 660 degrees Celsius melt point. This prevents damage while still allowing excellent bonding.
The key is filler metals that wet and adhere perfectly to aluminum surfaces to facilitate flow and bonding.
What are the Differences between Brazing and Welding?
Unlike welding, the brazing process needs no melting or harming the aluminum sheet, tube, rod, or other components themselves. They minimize distortion, which is important for delicate parts. Joining dissimilar metals and thin metals is possible with brazing. They also allow larger tolerances and gaps between pieces, and they only need simpler equipment and processing. For components where welding causes issues, brazing is your best alternative. The lower temperature also permits automation.
Popular Aluminum Braze Filler Alloys
Al-Si: Excellent wetting, most commonly used
Al-Zn: Controllable flow, good for tricky joints
Al-Ge: Low melting point, safe for sensitive parts
Magnesium is added to many alloys to boost wetting. You may consider working with a brazing expert to select the optimal composition for your needs.
Three Components of Aluminum Brazing
Aluminum Brazing Sheet
An aluminum brazing sheet is a flat-rolled aluminum product designed for brazing different parts and components. Its production involves cladding two layers of aluminum alloy onto a core material through a hot rolling process. The resulting brazing sheet offers outstanding corrosion resistance, thermal conductivity, and strength.
Aluminum Brazing Tube
It’s an aluminum product with a hollow cylindrical shape, serving diverse purposes like air conditioning, heat exchangers, and radiators. The manufacturing process involves brazing aluminum sheets or strips to create a seamless tube.
Aluminum Brazing Rod
It is a solid cylindrical-shaped product made of aluminum, and it is used for various applications such as welding and brazing. It is produced by extruding aluminum through a die to form the desired shape and size. Aluminum rods are available in various alloys and sizes to meet the specific requirements of different applications.
Different Brazing Methods for Various Operations
Torch and Furnace Brazing
This is applicable for manual heating for small batches.
Dip Brazing
This brazing method uses a flux tank and molten filler bath. This is highly efficient and is great for large volumes.
Induction Brazing
This enables continuous automated brazing due to localized heating from induction coils.
Regardless of the process, safety gear is non-negotiable when brazing.
Brazing Aluminum the Right Way
To effectively braze with excellence, observe cleanliness in material preparation. Use only fresh fluxes and filler alloys. You must follow strict temperature protocols. Design joints to minimize stress raisers and confirm parameters with test runs before production. And finally, inspect your joints thoroughly.
In conclusions
Following the principles outlined here will have you brazing aluminum sheets, aluminum tubes, and aluminum rods with the best, from concept to production. With smart design and process control, you can make aluminum’s full brazing potential for amazingly robust bonded assembly. Feel free to contact YK- Longshun to learn more.