"Adjustable ring mode technology—a welding method that couples two laser beams to one fiber—can boost throughput, reduce costs and improve quality,” says Marc Auger, sales development manager for Coherent Inc.

July/August 2019 - Q: What is adjustable ring mode (ARM) technology and what trends have pushed it to the forefront?

A: In 2018, we introduced our CleanWeld technology. It represents a novel approach to fiber laser welding that can reduce spatter by up to 80 percent  while minimizing cracking and porosity. Process consistency is enhanced, while some welding processes can be performed with as much as 40 percent less laser power.

As part of the CleanWeld approach, ARM allows the user to tailor the beam profile from a pure Gaussian to a ring or donut and any combination in between. New, higher strength grades of steel are difficult to weld with standard laser systems. Manufacturers have also been looking to reduce costs by eliminating filler wire in aluminum welding. These two trends have been the main drivers behind development of this laser technology. Manufacturers that want to harness its capabilities need to understand how it works and how to use it.

Q: What should a manufacturer look for?

A: Manufacturers need to look at what materials and types of products they want to weld to make sure that they select the correct laser size and type. With ARM, it is possible to select a single laser to perform tasks that used to require multiple systems.

Q: How does a fabricator evaluate whether this laser welding method is appropriate for an application?

A: At Coherent, we have an extensive database of all the material combinations that we have welded. This knowledge base allows us to evaluate and recommend the type of laser welding system a fabricator should use. We encourage customers to visit one of our applications labs with the material combinations they want to join. Our application engineers can help them evaluate the job and understand how the machine will function on their shop floor. Working one on one with a customer also gives them the assurance that their requirements will be met.

Q: What equipment features and functions should a fabricator consider and what performance advantages can users expect?

A: Since the Coherent ARM fiber laser was developed off our existing fiber laser technology, it is compatible with current welding optics and can be retrofitted into existing systems. The ability to tailor the laser beam profile across the system’s operating range has demonstrated quality and speed improvements in more complex welding applications using remote welding or seam tracking systems.

Besides being able to successfully weld some of the new grades of steel and aluminum, users can expect to see quality improvements, such as reductions in weld spatter and surface defects like pinholes.

The ARM laser also provides faster welding speeds using less weld power. Users are seeing a better return on investment. As a result, ARM is being adopted in a diverse number of applications including zero-gap welding of galvanized steel, automobile powertrain component welding, and aluminum and copper welding for electric car batteries. FFJ

Marc Auger is sales development manager for Coherent Inc., Santa Clara, California. which develops lasers and laser-based technology for scientific, commercial and industrial customers.