The Complete Guide to Laser Welders: Technology, Applications & How to Choose

Laser welders are replacing traditional welding processes because of their incredible speed, high precision, and exceptional weld quality. But still, they are new to many.

Whether you want to buy a laser welder or learn what it is, this guide will give you every important piece of information you need. We will dive into laser welders and their working process.

We will discuss the types of laser welders, the benefits they offer, typical industrial applications, safety considerations, and how you can pick the right laser welder for yourself.

What is a Laser Welder?

A laser welder uses a highly focused beam of laser to heat the material. It targets a tiny spot at a time and throws a high-energy density at the area. Which increases the temperature of the material quickly and changes its form from solid to liquid. It fuses both materials or pieces together, and upon solidification, a strong bond is created.

A laser welder consists of several primary components: Laser Source, Beam Delivery System, and Control System.

The laser source generates the laser. And it could be:

• Optical fiber doped with rare-earth elements, such as ytterbium, erbium, or neodymium
• Electrical discharge tube with a mixture of gases (CO2, Nitrogen, and Helium)
• Crystal rod made of yttrium aluminum garnet (YAG) that is doped with neodymium ions (Nd)
• Semiconductor chip made of gallium arsenide (GaAs)

After the production of the laser beam, it is directed to the material through a Beam Delivery System. It could consist of a series of mirrors and lenses or a fiber optic cable, depending on the type of laser.

Finally, there is a control system to control the laser beam. It helps in adjusting the parameters, such as laser power, speed, and other characteristics.

How Does a Laser Welding Machine Actually Work?

The working of laser welding machines differs depending on the type of laser used. There is a slight difference because of the different laser source, delivery medium, etc.

Fiber lasers are the most common types of lasers used in welding machines. Let's see how they work to weld metal pieces.

Firstly, the laser source plays its role. There is a flexible fiber optic cable doped with rare-earth elements, such as ytterbium. To pump these special elements, electrical energy is passed through laser diodes to emit light.

The light from diodes pumps the elements and compels them to emit laser light, which is responsible for welding. Then the laser light passes through the optical fiber and is amplified through back-and-forth reflection.

The light goes to the beam delivery system that transports it to the laser head or welding head through a fiber optic cable. Finally, the laser head uses lenses and mirrors to focus the light on a tiny spot. It increases the energy density and makes it capable of transferring intense thermal energy.

When the focused beam falls on the metal, it instantly transfers heat and increases the temperature. In no time, the temperature reaches the melting point of the metal and creates a molten pool. The molecules of both metal pieces fuse in the molten pool. And when the pool solidifies, it creates a very strong joint.

In laser welding, there are two primary processes: Conduction Welding and Keyhole Welding. They are meant for different purposes and applications.

Conduction Welding works on the principle of thermal conduction. It uses a low-power laser beam to heat the metal surface. When the beam falls on the metal, the heat is evenly distributed. It creates a shallow and wide molten pool, and the heat is conducted further to create a weld. The penetration is minimal, and there is no vaporization of the metal.

It's an ideal welding mode for thin materials and delicate components. It has a minimal heat-affected zone (HAZ), which is why it is used for metals with low melting points and to reduce the risks of distortion. It creates aesthetic welds and is used for jewelry, electronics, medical devices, and other high-precision and delicate jobs.

Keyhole Welding, on the other hand, uses a high-power-density laser beam. It penetrates deeply into the metal and also vaporizes it.

Due to vaporization, a cavity is created in the molten pool, which is known as the Keyhole. As the laser moves forward, the molten metal around the keyhole flows and solidifies to create a strong, deep, and narrow weld. To fill the cavity, often a filler material is used.

The weld is extremely strong, which is why it is preferred for heavy-duty applications. It is mostly used in the aerospace and automotive industries. Due to deep penetration and intense energy, it is not suitable for delicate jobs and materials with a low melting point.

Key Advantages of Using a Laser Welder Over Traditional Methods

Laser welding is gaining popularity over time, and it is also replacing traditional welding methods in various sectors. It is because of the key advantages it offers.

Minimal Heat Affected Zone (HAZ)

Laser welding focuses a tiny area with a highly focused beam. It increases the temperature of the target area and does not allow the heat to travel far and wide.

That said, the heat-affected zone in laser welding is minimal. The surrounding area of the metal does not go under heat stress, unlike other welding methods.

Therefore, it is an ideal method for welding delicate materials. It does not distort the metal or the surrounding area. Moreover, the metal does not lose its properties due to heat stress.

Exceptional Precision and Control

With laser welding, it is possible to weld small objects, as tiny as electronic components. It is because of the focused laser beam or tiny spot.

It offers exceptional precision, which is recommended for intricate jobs and complex components.

Moreover, it offers precise control options to the welders. They can control the heat by adjusting parameters. It ensures incredible weld quality and perfection.

High Speed and Efficiency

Laser welding is much faster than traditional methods.

In common welding processes, the MIG welder is quite fast. But laser welding is at least 8-10 times faster than MIG.

That said, it allows welders to weld quickly and save time. It increases efficiency and productivity, which is why mass manufacturers go for laser welding.

Non-Contact Process

In traditional welding methods, the electrode or filler material touches the workpieces to create the arc. Which means there is a contact.

On the other hand, laser welding is a non-contact process. There is no physical contact between the machine and the workpiece. It is just the laser beam that welds.

Because of this, there are fewer chances of contamination. The weld is exceptionally clean and smooth.

Secondly, there is no wear and tear of the electrode or laser head. You don't need to replace tips frequently.

The non-contact process also offers flexibility. It can be used to weld difficult-to-reach areas. It can even be mounted on a CNC machine or robotic system to automate the process.

Versatility in Materials

Laser welding machines can work on a wide range of materials.

They can weld stainless steel, mild steel, carbon steel, titanium, aluminum, nickel alloys, brass, galvanized sheets, magnesium, etc.

Therefore, it can be used for multiple jobs and projects. One laser welder is more than enough. It can even weld dissimilar metals, which is quite difficult and often impossible with traditional welding methods.

Laser welding is not limited to welding metals. It can also weld plastics, and is heavily used in the automotive industry because of this.

Common Types of Laser Welders: Fiber, CO2, Nd:YAG, and Diode

Laser welders can be divided into four types based on their laser source and welding process.

Fiber Laser Welders

Fiber laser welders are the most common laser welders and are considered the industry standard. They use a fiber optic cable for the generation and transfer of laser light.

They are extremely powerful and suitable for industrial applications. They are extremely efficient, which reduces the running cost. They are extremely reliable and produce exceptional quality welds with incredible strength.

They require minimal maintenance and have a long life compared to other welders. Secondly, they are compatible with a wide range of materials and thicknesses, which makes it a versatile machine.

The speed of fiber laser welders is commendable. They are suitable for high-speed and high-volume applications.

CO2 Laser Welders

CO2 laser welders use a mixture of gases to generate laser beams. They contain a discharge tube that generates a laser when electricity is passed.

They are specifically used for welding plastics, ceramics, and various other non-metals. They are not effective for metals because of the longer wavelength of the laser.

They are capable of producing immense power, so they can even weld thick materials. They are mostly used in the automotive industry, shipbuilding, etc.

Nd:YAG Laser Welders

These are solid-state lasers that use a solid crystal to produce lasers. They offer high peak power, which is usually utilized for deep penetration and spot welding.

They can be used in both continuous and pulsed modes. They are also suitable for precision welding and micro-welding.

Diode Laser Welders

Diode laser welders use high-powered laser diodes for the generation of laser beams. They are compact and suitable for small projects, DIY, and low-penetration welding.

They do not produce immense power like other laser welders, but the power is more than enough to join thin or intricate metal pieces.

Top Industrial Applications of Laser Welding Technology

Laser welding is a preferred technology in various industrial applications and sectors. Here are some of its use cases.

Automotive

Laser welding is used in the automotive industry to weld thin metal sheets to create the structural frame. It is better than spot welding as it is strong and durable. Plus, it welds the sheet without causing any distortion.

Secondly, laser welding is used to join intricate parts of engine and powertrain components. Within minimal HAZ and controlled heat, it ensures quality and a strong weld with precision.

Another common use of laser welding is assembling battery packs. The cells in the battery are joined through laser welding. It can join delicate components and battery terminals with perfection.

Medical Device Manufacturing

Medical devices are quite delicate, which is why laser welding is the best option. It is used in making intricate medical devices, such as pacemakers and orthopedic implants. It ensures a clean and contaminant-free weld with extreme precision.

It is also used in joining catheters and guidewires. It can weld these delicate materials without damaging heat-sensitive materials.

Aerospace

In the aerospace industry, laser welding is used because of its high strength, seamless welds, and versatility.

It is suitable for welding delicate and lightweight materials as it has minimal HAZ. It welds thin metals without harming their properties and shape. It plays an important role in the making of ariframes.

It is also used in joining jet engine parts, such as turbine blades and fuel nozzles. It offers enough strength to these critical parts that are under extreme stress.

Electronics

Electronics involves delicate components, and laser welding is used to join them. It can be used for micro-welding to join tiny components and elements to the circuit board.

It is also used for joining battery terminals and contacts. Along with that, it can help in creating sensitive enclosures, such as the casing or metal housing of smartphones and laptops.

Jewelry Manufacturing

Laser welding is an excellent process for jewelry manufacturing and repairs. It can join delicate pieces with excellent strength. After joining, there is no post-processing or excessive cleanup required. The join looks authentically pleasing and noticeable.

How to Choose the Right Laser Welder: A Buyer's Checklist

This is the core commercial section. Provide actionable advice for someone considering a purchase. Create a checklist of factors to consider:

Material Type and Thickness

The first thing you need to consider is the materials you want to weld using the laser welder. While purchasing one, you need to ensure the welder is compatible with the materials you want to weld.

Usually, laser welders are compatible with a wide range of materials, such as stainless steel, carbon steel, mild steel, aluminum, nickel alloys, brass, magnesium, titanium, zinc alloys, etc.

The second important thing is the thickness of the material. For instance, if you want to weld thin materials, a laser welder of 1,000 to 2,000W is more than enough. However, if you want to weld thick materials, you need more power, such as 5,000 to 6,000W.

Check the power of the laser welder to get an idea. Usually, manufacturers specify the thickness that welders can work with.

Required Weld Quality and Speed

Before buying a laser welding machine, you need to know the working modes. Laser welders can operate in continuous mode and pulsed mode. Depending on your needs, you need to check the modes the machine offers.

For deep penetration or keyhole welding, a continuous mode is necessary. And if you want to weld delicate items or do conduction welding, you need pulsed mode.

Laser welding is often a preferred choice because of its high speed. But how high? It varies from one machine to another. Take a look at the speed of the machine. Usually, manufacturers mention the length you can cover in a specific time.

Automation Needs

You can opt for a handheld laser welder or an automated/CNC/robotic laser welder.

The handheld laser welder has a laser torch that you need to move manually to perform welding. There is nothing automated in it. It is ideal if you work on a wide variety of projects on a small scale.

But if mass manufacturing is required, automation is a must. The machine automatically moves the laser head to weld the material. It could be controlled using a CNC, and in many cases, a robot arm is used to perform welding.

Budget and Operating Costs

Laser welding machines are quite expensive compared to traditional welding machines. The upfront cost is very high. However, the operational cost of laser welding is lower than that of traditional methods.

While buying the machine, the purchase cost isn't the only important factor. It's a one-time investment. The more important areas are electrical efficiency, maintenance contracts, and consumables.

Get an idea for the electricity consumption of the machine. Secondly, consider the maintenance cost, spare parts availability, and who will perform maintenance.

Laser welding also requires some consumables. The machine could use a filler material and shielding gas. Moreover, you need to replace some components, such as gas nozzles, protective lenses, and coolant filters, over time.

Space and Facility Requirements

For using a laser welder, you need an adequate facility. Firstly, consider the size of the laser welder. Some laser welders are compact and can be used in the garage. They are for light-duty tasks.

But in heavy-duty applications, high-powered laser welders are used. They are big in size and have special power requirements.

Check the operating voltage of the machine and whether it is single-phase or three-phase. High-powered machines require commercial electricity.

Also consider the cooling requirements for the machine. It might require water cooling, in which water or coolant circulates through the internal component of the laser machine to regulate its temperature. It is recommended for high-power lasers. Small laser machines mostly rely on air cooling that uses fans and heat sinks to effectively dissipate heat.

Operating a Laser Welder: Safety Protocols and Best Practices

Handling laser equipment requires extra care, and it's the non-negotiable part of laser welding. There are some safety protocols and best practices to ensure the safety of the welder, workers, and facility.

Laser Safety Enclosures: This special enclosure is necessary to prevent laser leakage and accidental exposure to the laser. The machine should contain a safety enclosure and a light-filtering cover.

Personal Protective Equipment (PPE): Welders must be equipped with appropriate PPE. They need to wear safety glasses to protect their eyes from laser beams. Specialized goggles that are rated for specific wavelengths are required for optimal safety. Welders also need to wear welding gloves and protective clothing to protect their hands and body from heat and spatter.

Fume Extraction: When a laser strikes the metal and airborne particles, it generates fumes. A proper fume extraction system and ventilation are necessary to remove hazardous metal vapors.

Training and Compliance: Before operating industrial-grade laser machines, welders need to get certified training. Even if they are certified, they need training for the specific machine. There should be written SOPs, safety protocols, and maintenance schedules to ensure everyone's safety.

Conclusion

Laser welding is the future. Even though it's not very common yet, it's gaining attention over time. Because of its extraordinary benefits and features, it is an ideal option for many applications. We have explained what a laser welder is and how it works. From benefits to applications, we have discussed everything to help you select the right laser welder. While buying any laser welder, remember the important considerations we've discussed to make the selection easier.