How Strong is Aluminum Brazing?

How Strong is Aluminum Brazing?

Brazing is a different process than welding and is a pretty popular technique to join metal plates. Brazing aluminum has a number of advantages that can even make it even better than welding. In terms of quality, both have similar results.

However, on many other aspects, brazing can be a more ideal choice to go for. In this article, we will talk about various factors about brazing aluminum and explain whether it is strong or not. We also added some other necessary information regarding the brazing method and sometimes compared it to welding.

Does Brazing Create Permanent Joint?

When construction workers braze aluminum joints, they don’t plan to separate them in the future. The very aspect of brazing is to keep it permanent. On the other hand, joining two aluminum plates using screws, nuts, and bolts is mostly for separating them at a later date. In fact, it will be a big hassle to separate brazed aluminum willingly. So, yes, brazing creates permanent joints on aluminum plates.

What Are the Benefits of Brazing Your Aluminum Plates?

Brazing your aluminum plates comes with a number of advantages. Here are some of them below

  • Brazing your aluminum is done at a lower temperature compared to welding. The suitable heating necessary for this is from 1150 to 1600-degree F.
  • Brazed aluminum is always automated. So, it is much faster to work with this.
  • You can join different metals with aluminum plates together using the brazing method. It is unlike welding, where the joined metals need to be similar.
  • Another good thing about brazing is that you don’t need to melt the base aluminum. So, it is comparatively easier than welding to control the temperature. Brazing is also easier to master than welding.

How Strong Is Aluminum Brazing Joint?

Aluminum brazing does not lack one thing, and that is strength. You can braze aluminum and be sure that the metals will be joint permanently unless you willingly separate them. Joining aluminum with brazing can be as strong as or even stronger than the base metals being joint normally. So, you will not need to worry about the strength of a brazed aluminum joint no matter where you are using it.

Comparing Brazing Aluminum with Other Joint Methods

Let us see how strong aluminum brazing is when we compare it with other joint techniques like welding or soldering.

Welding vs Brazing

Welding joints can get even stronger than the base metal itself. As a result, welding is a way to strengthen the metals. In terms of strength, welding is mostly stronger than brazing. But remember that brazing has all the other benefits mentioned above.

Welding vs Soldering

Let’s say that soldering is like a low-temperature version of brazing. However, brazing will create a much stronger joint than soldering. When soldering aluminum, it needs a temperature below 840-degree F. Any temperature above is considered brazing. Soldering is weaker than both brazing and welding.

We should mention that you must never braze aluminum or any metal parts that will be used in places with over 3632-degree F. In brazing, you need to heat the base metal and melt the filler rod to fill the joint seam.

Meanwhile, a welding process works by melting both the base metals and pressing them against each other to fuse them. For brazing, the joint is basically made of the filler rod, which has a lower melting point than the base metal. But as welding only fuses the work pieces, the final result will have higher heat resistance. That makes the welding joint stronger than brazing. It is similar to any metal, including aluminum.

Soldering also uses filler material, but the filler for soldering has even a lower melting point. Thus, soldering joints are even weaker than brazing and should only be used on light-duty works, like circuitry, jewelry, or wiring.

Frequently Asked Questions

How Should I Clean Aluminum Before Brazing?

There are a lot of ways to clean aluminum to make them ready for a braze. Many people will go for a wire brush. However, some think that wire brushing may scratch the metal. In that case, you can try vapor degreasing to apply degreasing solvent. Alkaline also works fine. To remove oxide, you may need to use appropriate chemicals. Your initial goal has to be to wipe all the grime and oil off the aluminum part.

What Type of Brazing Rod Should I Use for Aluminum?

You will need a brazing rod that can heat up enough to go through the anodized layer of aluminum. In case you don’t know, anodize is a metal layer that stays on the base aluminum. There are special filler rods made for brazing aluminum. For example, the 4043 is an excellent one with a high melting point of 1065-1170-degree F. 4047 is also a suitable rod for this job.

Final Note

Whether aluminum brazing is strong enough or not depends on your application to an extent. If your work piece is for operating at a very high temperature of 3632-degree F, brazing will suffice. But anywhere below that, it will work just fine.

Many workers prefer brazing copper or aluminum more than welding since it is more cost-effective and can join different metal types. If done right and with a quality brazing rod, brazing joints can have a really similar strength as welding joints.

Last Updated on 2 weeks by Richard Boyer

  • September 9, 2021
Richard Boyer
 

Richard Boyer has been a professional welder for over 27 years of his life, and now he is a trainer and blogger providing critical information to anyone interested in welding. He is helping out both hobbyists, novice and professional welders to learn newer and better techniques. Read more about me

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