By now, we have all seen the Youtube, Facebook, Instagram videos of someone casually picking up a “laser gun” and welding materials together effortlessly. Well, now in 2023, this technology is here and is becoming available for industry. At the time of writing this article though, laser welding is probably not accessible to everyone due to the costs of the machines involved and the hazards that class 4 lasers used in the welding process can bring.

With that said laser technology is a huge advance in welding, with unquestionable benefits for certain applications. Undoubtedly, laser is likely to be the future of welding as technology is improved and costs come down.

This article has been put together to discuss the process, the benefits of laser welding, associated hazards and some of the terminology and functions of a laser welder.

How Does Laser Welding Work?

Laser stands for Light Amplification by Stimulated Emission of Radiation. The focusing of this laser beam onto a joint between 2 materials creates heat, melts their edges, and fuses them. It is this concentrated heat source that can be utilised in the welding process, replacing the electric arc commonly associated with conventional welding techniques such as MIG, TIG or MMA welding.

There are primarily 3 different types of laser welder, but as we supply fibre lasers, we will discuss this process only:

A fibre laser welder incorporates fibres within the machine which absorb raw light from pump laser diodes, resulting in the creation of the laser beam. The optical fibre within the machine is doped with a rare earth element, which, depending on its type, can produce different wavelengths of light. Fibre lasers offer safer operation, better quality and more power than the older laser technologies not mentioned here.

Filler or No Filler?

Some laser welding processes, much like TIG welding, can be performed without the use of an additional filler metal. If a joint is tight fitting, with little to no gap, the laser can concentrate the heat onto the joint to create a seam weld. Commonly called autogenous welding, the melting and solidifying of the 2 materials coming together requires no additional filler material.

If there is a gap between the 2 parts to be joined, an additional filler material can be used. The addition of filler material can improve the weld profile, reduce solidification cracking and improve the welds mechanical properties. Our Weldstar and Max Photonics laser welding machines come with wire feed units. These work much like a cold wire feed in TIG welding, where a wire is removed from a spool in the wire feeder, and is pushed through a guide tube to the head of the laser torch. The filler is then introduced to the weld puddle generated by the heat of the laser beam. The rate at which the filler is introduced to the weld can be adjusted to suit the application.

Benefits of Laser Welding

Currently, laser welders are fairly expensive to buy and implement, and this is where the benefits of the process should be assessed. Is the return on investment worthwhile?

Where cost can be a major factor in the original outlay for the equipment, this may quickly be negated with increased efficiency and fewer man hours to produce the same results. This is where laser welding has the edge…..

Speed – Laser welding can be up to 4 times faster than traditional MIG or TIG welding processes.

Fume – Laser welding tends to create less welding fume than conventional welding methods

Skill – The operator need not have the skill required to be able to TIG weld. Less labour costs and a decrease in training time.

Less Heat – The concentration of heat, focussed onto a small area makes the heat affected zone (HAZ) smaller. The amount of heat in the workpiece is decreased due to the speed of the process as well as the smaller HAZ.

Lower Heat Distortion – Less heat into the workpiece results in less distortion which otherwise, can create warping and issues with subsequent fit-up.

High Precision – The controllability of the laser beam results in the ability to focus on a very small area. As a result, laser welding is well suited to components requiring high precision, particularly on small parts or thin metals.

Laser Welding Hazards

As previously mentioned, laser welding is possible due to the concentration of an intense source of light composed of different wavelengths. Much of the light that is emitted from the torch onto the workpiece is reflected back into the environment, creating hazards for the user, as well as those in the vicinity. Much of the light used in laser welding is invisible too, so the hazard is not readily apparent.

Radiation: Much like traditional electrical arc welding, both visible and invisible light radiation is produced. The high levels of blue light and ultraviolet radiation (secondary radiation) produced can be reflected back into the room. The radiation from the reflected light can seriously burn eyes and skin quickly and permanently.

Fumes: Like any welding process, laser welding creates fumes and mists when they vaporize metals. These fumes may be invisible to the eye but form a respiratory hazard that should not be overlooked. The introduction of adequate localised exhaust ventilation fume extraction as well as respiratory protective equipment should be used to manage the risk to operators’ health.

Accident: The laser head being controlled by a person or by a robotic arm may accidentally become pointed away from the workpiece. To minimise this risk, a class 4 laser enclosure or dedicated room should be used to protect other persons in the working area. A laser enclosure is a purpose built screen or roofed structure which can be used by the person carrying out welding with a laser. The door to the enclosure would have an indicator light to show when the laser is in use. A monitor TV screen can be mounted to the outside of the enclosure to maintain sight of the operator to check welfare. The enclosure will also help to protect persons from radiated light hazards too.

Fire: The intense heat from the concentrated light source is hot enough to combust flammable materials. Risk should be minimised by ensuring any potential fuel sources are removed from the area surrounding the welding activity.

Eye Damage: Persons using or observing laser welding must take precautions to protect their eyes from the incredibly bright light source. It is important to use safety goggles of the correct wavelength for the equipment being used.

Laser Safety Officer

Any company with laser welding capability should have a dedicated laser safety officer (LSO) on site. The LSO is responsible for the safe running of the laser welding process, checking the safety within the process, the laser enclosure conformance, and that any operators are supplied with the correct personal protective equipment.

TERMINOLOGY

For many of us, laser welding is a completely new process. Many hazards and principles are true of traditional welding methods. Here we look at some specific laser welding terminology, their meaning and their practical implications:

Wobble

A laser welding machine will have a “wobble parameter” which will be expressed in mm. The wobble of the laser increases the beam diameter. The movement of the beam creates a larger area which in turn increases the width of the weld. Wobble is particularly useful for hard to weld reflective materials such as Aluminium and copper. Furthermore, the wobble and increased beam diameter can assist when a gap is present between the two parts being welded together.

Wobble Frequency

Wobble frequency is the speed at which the wobble takes place. An adjustment of wobble frequency can affect the heat input into the weld seam. By increasing the frequency, less time is spent on a focussed spot, hence decreasing heat input and potentially reducing penetration.

Conclusion

Laser welding is probably the future of welding and for some, will have some huge benefits compared to traditional techniques. Whilst a hefty initial outlay, the return on investment comes from precision and increased productivity.

Our laser welders come from our trusted supplier Wilkinson Star, a company we have been in business with for many years. Their customer service is second to none and they invest heavily to ensure products are well supported with trained staff and parts availability in the unlikely event of a breakdown. Where a machine cannot be fixed in a timely manner, a loan machine will be left on site to ensure downtime is kept at an absolute minimum. This is particularly important when investing in equipment that is relied upon in production environments.

If you are considering a laser welder, feel free to make contact. We are able to organise demonstrations at the Wilkinson Star site in Manchester, or we can arrange for test pieces to be welded up under video conditions.

Please feel free to take a look at these demonstration videos on the following link: