How Does Laser Welding Work?

Welding is not new and has been used for decades to connect two metal pieces. However, laser welding is a relatively new technology that makes welding easy, quick, and less expensive. Many people need to learn how laser welding works using the latest technology.

In this article, I will explain the basic principles and workings of laser welding. Not only the working, but you’ll also get the comparison of laser welding with old-fashioned traditional welding to know which one suits your needs.

Working in Laser Welding

Everyone knows that welding is when we join two metal pieces together. When this is done with the help of laser beams, it is called laser welding. There are two significant types of laser welding. I will explain and guide you on how those types work in the section below.

1. Heat Conduction Welding

In welding, lasers are applied to the surface of metals to join them. However, those lasers melt the metals at their melting points. When the metals melt, they fuse and bind with each other. 

When these fused parts are set to cool, they ideally solidify and make strong joints. This type of laser welding is usually suitable for routine tasks. Thin materials are usually welded with this type at a very high welding speed.

Heat conduction welding does not offer a solid weld. However, you can achieve excellent smoothness at the weld. In short, the laser beam, which has a lower power of 500W, combines two metals or thermoplastics.

2. Deep Penetration or Keyhole Welding

In this type of welding, the laser beam melts the metal at its vaporization point instead of at its melting point. The beam is so powerful and focused at one end of the metal that it penetrates and makes holes.

When the metal where the beam strikes vaporize, a small hole is created, and the laser beam goes inside the hole. This hole is later filled with the melted metal or filler. Keyhole welding is usually done with thicker material.

This type is more powerful and offers durable joints and connections. Keyhole welding is used on the industrial scale as it requires stable and robust welds. In a nutshell, Keyhole welding provides strength, while heat conduction offers smoothness at the welds.

Many other types of laser welding exist, including pulsed, diode, gas, and solid-state laser welding. If you’re interested in exploring the specifics of each, you can learn more about them. However, only some of these types are very common.

What Kinds of Materials Can Be Welded Using Laser Welding?

All kinds of metals and thermoplastics can be readily welded with laser welding. However, make sure that the metals that you’re going to solder are not rusted and weak. It should be rust-free and robust enough to bear the heat of lasers.

Here is the table showing the material that can be welded with the laser welding process:

CeramicsAlumina, Zirconia
CompositesCarbon fiber-reinforced plastics (CFRPs)  
GlassBorosilicate, Quartz
PlasticsABS, Nylon, Polycarbonate
MetalsAluminum, Brass, Copper, Nickel, Steel, Titanium etc

Laser welding is commonly used in many industries, including automotive, aerospace, medicine, and jewelry. Companies have started laser welding methods and robots to automate the welding process. They control the bots with fibers.

Laser Welding VS Traditional Welding – Mechanism and Differences

Laser welding is an advanced method with better performance than traditional welding methods. I will explain the differences between these two weld types in the section below.

● The laser welding method is accurate and precise. It produces no distortion on the metal surface or at the joints. The traditional welding method is not very precise and distorts to some extent.

● Laser welding is clear and focused. It does not produce a wide HAZ (Heat Affected Zone), whereas traditional methods expand the affected area, making it look bad.

● One of the most significant advantages of laser welding is that it quickly completes the work. Within seconds, you can join two pieces of metal. However, the classic methods of welding take a lot of time.

● Modern laser welding is safe to use and operate. In fact, welding with lasers is automated in prominent industries, and robots complete the process. Traditional methods cannot be automated at all.

● The conventional methods are generally cheaper than the laser welding method. However, their quality is not as good as you get with laser welding. There is a myth that conventional approaches are cheap. Laser welding is more cost-effective as it saves time and does not require any expert team for its operation. As the laser joins the metal in a second, you’ll need power for a few seconds, and power consumption will be lower.


There is no doubt that modern laser welding technology has revolutionized many industries. The work that used to be done in days is now completed within hours and minutes. More and more industries and companies are using this method of welding.

Heat conduction and keyhole laser welding are two efficient ways. Highly focused and powerful lasers melt the metals and fuse two parts. The keyhole method is slightly better as it offers solid welds.

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