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Today we will discuss how laser welding aluminum is performed: what you have to know about the material itself to avoid mistakes; which parameters, wire, and gas to use.
Aluminum and its specifics
If you’ve ever seen this material, then you personally know that it’s highly reflective. And that causes problems for laser metal cutters, reflecting emitting, and laser welding machines are no exception.
Aluminum alloys, which are nonferrous metals, are highly reflective and have minimal absorption of laser energy. Furthermore, fast heat loss or laser reflection may occur during welding because of their high thermal conductivity.
Due to these characteristics, aluminum is usually treated with a fusion welding process. That means a big amount of heat is generated in the small zone to fuse two or more metal pieces together by making them reach the melting point.
The fact that only a small part is being heated is very important when working with aluminum since it has high thermal conductivity: the heat is quickly spread inside of the material and may lead to overmelting or deformation.
Also, aluminum has a low melting point. That can cause workpiece damage. When processing this material, be careful and monitor laser welding machine power.
One more problem for operators to deal with is the oxide film covering the surface. The difficulty here is in different melting temperatures the film and aluminum have.
Furthermore, there are different aluminum series. They are divided by the additive components in the compound. The correct choice will help you to avoid problems and find the right filler material, wire. For laser welding aluminum, the following are suitable:
- 1050, 2219, 3003, 5052, 6061, and 4047 series;
- if you have to weld 6061, pay attention; you’ll have to use 4047 or 4043 as a filler. That’s necessary to avoid hot cracking problems. More on that subject down below.
Laser welding aluminum process
Pre-treatment
Before talking about maximum thicknesses and parameters, we need to complete this stage. The surface part that is going to be treated has to be cleaned.
First of all, aluminum may have a hydrocarbon residue. You can get rid of it by using acetone or alcohol-based solvents. However, do not use chlorine-containing cleaners: after being heated, they emit toxic fumes.
Second of all, you have to prepare surface with grinding or stainless steel wire brushes. Oxide film has to go.
Or simply turn on the cleaning mode on the Wattsan laser welding machine 4in1. With it you will be easily able to remove the oxide layer. In this way, the welding process will be at max convenience.

Welding
Now, let’s speak about parameters. We will be using a 4in1 laser welding machine with 3000 W power source as a reference.
— Aluminum, 0.5 mm thickness. For this one, use 400 W of power, laser frequency equals 5000 Hz, vibration frequency of 50 Hz, and the seam width should be 2.0 mm. Set the speed of the wire feed at 12 mm/s if using one.
— Aluminum, 0.8 mm thickness. Here, all settings are the same, except for the power. It should be 500 W.
— For laser welding aluminum of 2.5 mm, you need 1100 W power and a seam width of 2.5 mm. Everything stays untouched.
— For 4.0 mm aluminum, 1400W is required, a 3.5 mm seam width, and reduced wire feed speed of 8.0 mm/s.
Max welding thickness is based on the laser source power your machine has.

Post-treatment
Sometimes this stage may be needed: for example, seam cleaning or painting.
By the way, seam cleaning mode is available on the 4in1 or 5in1 laser welding machines with easy access: there is no need to change modules or lenses, only the nozzle.
Wire and gas
Wire
In cases when you have to use wire, we recommend aluminum ones. It may occur as a necessity if there are hot cracking or blowholes problems.
The wire itself for laser welding aluminum contains silicon or magnesium, or both. Check this.
One more important moment is the wire installation in the automatic feed system. You need to use U-shaped rollers, and the feeding tube has to be teflon and non-reinforced.
Gas
For laser welding aluminum the argon-helium mixtures are used. They provide good results. Nitrogen, on the other hand, is not recommended.
Laser welding aluminum machines
Wattsan has three lines of welding machines: 4in1 G1, 4in1 G2, and 5in1 G2 Pro. Each of them is suitable for aluminum processing.
Equipment may have any laser source by the client’s choice with preferred power. Also, all machines have the automatic wire feeding system in basic configuration: it speeds up the production and makes operators’ lives easier.
Laser welding machines have various functions: welding, continuous cleaning, seam cleaning, and cutting. There may be a fifth option like energy storage welding, but that’s a convocation for next time.

Conclusion
- Aluminum is highly reflective and has minimal absorption of laser energy. Aluminum is usually treated with a fusion welding process. That means a big amount of heat is generated in the small zone to fuse two or more metal pieces together by making them reach the melting point.
- One more problem for operators to deal with is the oxide film covering the surface. The difficulty here is in the different melting temperatures the film and aluminum have.
- For laser welding aluminum, the suitable series are 1050, 2219, 3003, 5052, 6061, and 4047.
- Pre-treatment is required and can be performed via acetone or alcohol-based solvents or laser cleaning mode.
- For laser welding aluminum wire, silicon or magnesium in the compound has to be used. Preferred gas—argon-helium mixtures.