Coherent launches new 4kW fiber laser welding system

05 Jun 2020

HighLight FL4000CSM-ARM developed at revamped Center of Excellence for Fiber Lasers in Finland.

Laser giant Coherent’s new HighLight FL4000CSM-ARM fiber laser builds on the success of Coherent HighLight ARM fiber laser series, which is already qualified for automotive applications, the company says.

The new laser enables “more advanced welding capabilities for high thermal conductivity metals, and aligns to welding requirements for e-mobility, energy storage, and general electrical interconnects consisting of dissimilar materials, such as copper and aluminum, and foil stacks that require precise control,” says this week’s launch statement.

The company adds that this technology “represents a significant improvement in simplicity, and overcomes the limitations of other joining technologies.” Problems in this area can include unstable welds due to welding head wear and the large heat affected zone caused by ultrasonic or standard fiber laser welding.

'Limitation busting'

The ability to move beyond the limitations of traditional fiber laser for welding thin conductive materials is possible because of the FL4000CSM-ARM’s dual beam output, in which a central beam is surrounded by a ring beam. The center beam has extremely high brightness (nominal BPP 0.6) allowing a smaller spot size compared to its multi-mode counterpart.

The small spot size, says Coherent, “results in very high laser intensity that minimizes heating of the material, and, together with the pre-heating effect achieved by the ring beam, significantly improves stability of the melt pool and therefore weld consistency that is a challenge when welding thin conductive materials.”

The FL4000CSM-ARM has been developed at the company’s recently expanded Center of Excellence for Fiber Lasers in Tampere, Finland and is available with an output power of 4 kW, comprising a 1.5 kW center beam and a 2.5 kW ring beam.

As with other Coherent Adjustable Ring Mode lasers, power in the center and ring beams can be independently varied and modulated. The CSM-ARM is supplied with a 15m-long process fiber, making it easy to integrate in virtually any production environment, and is compatible with the standard process heads from Coherent and other manufacturers.