Extending Precision Laser Welding to 5 kW

Coherent SmartWeld+ remote laser welding tool shapes welding seams and profiles with maximum precision and optimized heat input.

June 15, 2023 by Coherent



Applications such as e-mobility manufacturing are driving an increased need to weld traditionally “difficult” materials, like copper and aluminum, or to join dissimilar materials. Introduced in 2019, the Coherent SmartWeld+ precision remote welding head provides the precise energy distribution and penetration depth control necessary to successfully produce these types of welds. 

The new PH20 SmartWeld+ extends the range of this proven technology to lasers of up to 5 kW power. This makes it compatible with a larger selection of single-mode standard and Adjustable Ring Mode (ARM) fiber lasers including the Coherent HighLight FL CSM ARM, HighLight FL CSM, and PowerLine FL 1000/1500. The result is the ability to weld both thin and thick materials with unmatched precision at high speeds.   


What’s so smart about SmartWeld+?

SmartWeld+ achieves this combination of speed and precision by mating fixed beam delivery optics with a highly dynamic galvanometer scanning module (speeds up to 4 kHz). This is controlled by sophisticated software for producing a variety of pre-programmed scan patterns. These “smart” patterns move well beyond traditional beam wobble to encompass spirals, ellipses, and other complex shapes.  

In addition to higher power operation, software upgrades in the PH20 SmartWeld+ enable the system to dynamically adapt beam motion (pattern orientation, size, and oscillation frequency) to compensate for individual workpiece variations as measured by the vision system. When matched with an ARM laser, this beam control can be synchronized with high speed, independent modulation of the power in the center and ring beams. This provides an unprecedented level of spatial and temporal control of how laser power is applied. 

All this delivers more consistent weld quality and seam dimensions, while simultaneously relaxing part fit-up requirements. And, with an expanded 50 x 50 mm scan field, the newest SmartWeld+ can sometimes eliminate gantry movement for even greater throughput speed. 


A better weld

Results demonstrate the ability of SmartWeld+ to precisely control weld seam dimensions and shape, as well as reduce heat input. For example, the two photos compare welds from a traditional multi-mode laser (800 µm approximate focused spot size) with a much lower power, single-mode laser (30 µm approximate focused spot size) controlled using SmartWeld+.  


SmartWeld+ Multi-Mode
SmartWeld+ Single-Mode

A traditional multi-mode pulsed laser produces a weld (left) with uneven depth and a relatively large heat-affected zone, while SmartWeld+ paired with a single-mode fiber laser produces a weld (right) with uniform depth and strength, and minimal heat-affected zone. 


SmartWeld+ produces a weld cross-section which is more rectangular and 40% larger than the traditional approach. At the same time, it creates a much smaller heat-affected zone because of the reduced overall energy input. As a result, thermal stress and crack formation are minimized and weld strength is increased. 

Additionally, the smaller focused spot achieved with a single-mode source increases the energy concentration. This improves process stability on highly reflective materials – like copper or aluminum – which usually are difficult to weld, particularly with infrared lasers. 

Learn more about SmartWeld+.