COHERENT - ROFIN

New CleanWeld technology to optimize fiber laser welding results

Fiber lasers are being used successfully in many metal welding application, they don’t always deliver ideal results. To improve fiber laser welding outcomes, Coherent introduced CleanWeldTM, an integrated approach that delivers up to 80% spatter reduction, as well as minimal cracking and porosity. In addition to improved process consistency, it allows some welding processes to be performed with 40% less laser power.

One key element in the CleanWeld toolkit is the Coherent Adjustable Ring Mode fiber laser (FL-ARM). Instead of a traditional beam consisting of a single laser spot, the FL-ARM produces a central beam, surrounded by another concentric ring of laser light. Most importantly, the power in the center and the ring can be independently adjusted on demand from 1% to 100% of the maximum. The core and ring beams can even be independently modulated, at repetition rate of up to 5 kHz. FL-ARM lasers are offered with (total) output powers of 2.5 kW to 10 kW.

The FL-ARM spot configuration allows much more precise control over how laser energy is delivered during welding. For example, it can preheat material to reduce temperature gradients in the melt pool, keep the melt pool open longer to allow the escape of gas. The ultimate result is more uniform, consistent material penetration and higher quality, spatter- and porosity-free welds.

Coherent’s CleanWeld technology, including the FL-ARM, are particularly useful for welding traditionally “difficult” materials for fiber lasers. This includes zero gap welding of galvanized steel, welding aluminum lithium ion battery casings, welding powertrain components and hang on parts, and stainless steel profile welding.