Getting Started with Laser Welding

Posted by John Sutter on Sep 13, 2021 12:21:56 PM

With the rise of laser welding, the importance of understanding this process is absolutely critical. Once you have the basics down, you can begin to consider what it would take to incorporate this type of welding equipment into your facility.

Like anything new, a great start to learning is determining the advantages and disadvantages that come along with whatever you’re dealing with; in this case laser equipment as it relates to welding.

Advantages of Laser Welding

For starters, the laser process is significantly faster than any other welding process. For example, laser is ten times faster than a typical MIG welding process.

Laser welding limits the amount of heat that is delivered to your part. The longer you dwell on a part, the hotter the whole entire part gets. When things start to heat, especially metals, they begin changing shapes. They swell a little, and as they change shapes the metal will eventually distort. This them makes problems for the fit up, which is where you want the weld to go. Sometimes the weld joint is moving during the process where you are trying to weld it, which just makes it really difficult. Lasers move so fast that there’s almost no part deformation in a lot of the parts where there typically would be. 

Another advantage is that a lot of materials used in automobile manufacturing are higher carbon steels that are very sensitive to metal phase changes. This is where the chemistry of the metal goes through a change to its microstructure and it can be a permanent change to its solid state. Let’s say you have a piece of high carbon steel, which is used a lot in bumpers or door supports on automobiles in car manufacturing, if the heat affected zone of the weld heats up and cools down too much, it can be embrittled by a phase change called Martensitic transformation. This transformation is defined by the change from metal solid state becoming more of a crystallin structure that it was in its pliable or stampable state. This is a big deal and is driving the change to newer processes like laser welding.

Disadvantages of Laser Welding

Most often the biggest concern with laser welding is safety. Usually, laser welding systems are set up with robotic arms to ensure a higher level of safety. Using the robot allows for less human contact, which is important because it can be pretty unsafe for a person to hold a laser. You’re dealing with an invisible light that can absolutely fry your eyeballs. Your eye is really good at collecting all types of light, not just those visible on the electromagnetic spectrum. The problem is your brain doesn’t recognize that the light is really bright, so if your pupil does not dilate to limit the amount of light let in, you run into some major safety issues. It is so important to have the right safety gear and to limit human exposure.

At one point robots were a dangerous tool as well, until people understood them. It’s just one of those things… You have to know what you’re dealing with. People don’t realize that because they can’t see it, there needs to be extra care in making sure safety protocols are in place.

Another disadvantage is that laser welding is a very touchy process. The reason is the process spot is so small and it is moving so much faster than other applications. If your wire system isn’t up to the task, delivering with extreme precision and speed or your optics getting dirty and you haven’t kept up with maintenance, the performance of your system will suffer and likely cause you bad welds.

The clamping that is required, the part fit up, and the part cleanliness needs to be a lot more cared for. Dirty parts are going to get you in trouble because it makes the laser process more explosive, and since you are using a small beam, your process becomes more explosive leading to a lesser chance for a good weld.

In addition to this, the cost can get pretty high for laser welding applications. Let’s compare to a typical spot welder, which is going to you about $5,000-$7,000 for the entire package (meaning the weld timer, cables, and gun). Everything except for the robot and obviously the floor space to put everything. With a laser system, you typically have to make about a three-million-dollar investment to put one of these things into your facility. Reason being, you need a light tight enclosure, trained staff, a $100,000 laser, another $100,000 for the optic, $12,000 fiber optic cable… you get the point. It adds up quick and you still need to buy a robot. 3-million-dollars would be typical for an automotive four-laser-system. You can get a laser system that is a little on the cheaper end, which would run you about a quarter million to half a million dollars, but that would be just one laser.

With all things considered, these basic pros and cons will help determine whether or not laser welding fits with your facility’s needs. Understanding this process is the first step to success and without that you, will likely run into roadblocks that could have been avoided. Do your research, familiarize yourself with the process requirements, and define best practices to ensure you are ready to get started.

Interested in learning more about laser welding? Check out ABICOR BINZEL's laser equipment here.

Topics: Laser Welding