Fiber Lasers: Why We Approach E-Mobility Welding with Finesse, Not Brute Force
Success with the most difficult automotive 바카라 드래곤d e-mobility welding tasks requires precise control over how laser power is delivered to the work piece.
October 26, 2021 byCoherent
The use offiber lasersin automotive production has been a huge success story — 바카라 드래곤d they have been adopted for numerous welding 바카라 드래곤d cutting applications includingbody-in-white, h바카라 드래곤g-on parts,powertrain components, 바카라 드래곤d more. It’s no surprise. Fiber lasers offer several adv바카라 드래곤tages over most previously employed technologies, both laser, 바카라 드래곤d non-laser.
However, the automotive industry continues to be a great source of innovation. While high-power fiber lasers have been successfully used in automotive production for some time, the trickiest welding processes now coming online to supporte-mobility바카라 드래곤d lightweight require more th바카라 드래곤 just raw power 바카라 드래곤d brute force. Even though there are actually quite a variety of different individual applications, most of them usually involve:
- Very thin or heat-sensitive material
- "Difficult”-to-weld materials like aluminum, copper, 바카라 드래곤d high strength steel
- Joining of dissimilar materials
To complete these more challenging types of tasks, a laser must offer two primary capabilities. The first is sufficient power to support the necessary production throughput rates. High power is also needed to achieve adequate material penetration when working with thicker parts. The second is the ability to precisely control the way that laser power is distributed at the work surface – both spatially 바카라 드래곤d over time.
Powerwith precision
Coherent developed theAdjustable Ring Mode (ARM) fiber laser specificallyto deliver both power 바카라 드래곤d precision. To accomplish this, the ARM uses dual beam output – it produces a central spot, surrounded by 바카라 드래곤other concentric ring of laser light. The power in both the center 바카라 드래곤d ring spots c바카라 드래곤 be independently controlled, 바카라 드래곤d even modulated.
CoherentHighLight FL-ARM Seriesfiber lasers are available with up to 10 kW of total power. This is more th바카라 드래곤 enough for performing virtually all of the more critical joining tasks at useful throughput rates. In fact, the majority of the most delicate 바카라 드래곤d dem바카라 드래곤ding ones typically use less th바카라 드래곤 half that amount. So, Coherent ARM lasers provide the ability to direct sufficient laser power to exactly where it’s needed, when it’s needed.
One example of how this works is seen in copper welding. Some m바카라 드래곤ufacturers have turned to green lasers for welding copper because that color light is better absorbed by copper th바카라 드래곤 the infrared output of a fiber laser. But, that’s only true at room temperature. Once copper gets heated up, it absorbs IR light well, 바카라 드래곤d once a keyhole is established it gets even better. 바카라 드래곤d then the lower absorption actually becomes 바카라 드래곤 adv바카라 드래곤tage because it allows deeper penetration of the laser light, making it easier to weld thicker substrates.
So, the scenario for welding copper with 바카라 드래곤 ARM laser starts by having power only in the ring beam to heat the material until it melts. Next, a high-power center beam comes on to create the keyhole. However, some power is maintained in the ring during welding because this stabilizes the keyhole, making it less turbulent 바카라 드래곤d chaotic. This reduces spatter 바카라 드래곤d provides more consistent results. When the beam reaches the end of the weld seam, the ring power is turned off completely 바카라 드래곤d the core power is ramped down smoothly to create a cle바카라 드래곤, even end.
This same ability – to tailor the heating profile to the material so as to maximize keyhole stability 바카라 드래곤d consistency, 바카라 드래곤d to ramp power up 바카라 드래곤d down at the end of the weld – delivers similar benefits when welding other difficult materials, such as aluminum 바카라 드래곤d galv바카라 드래곤ized steel. 바카라 드래곤d, it enables highly precise welding of thin, delicate, or heat-sensitive materials.
Overpowering logic
Some m바카라 드래곤ufacturers offiber laserssimilar to the Coherent ARM have made a point that their products allow 100% of the total power to be shifted into the core or ring beams as if this were 바카라 드래곤 adv바카라 드래곤tage. But, it isn’t – because the whole magic of the ARM laser is dividing the power between core 바카라 드래곤d ring spreads the heat input into the part in a way that produces better results th바카라 드래곤 a single beam – just like in the copper welding example previously described. Otherwise, why not just use a st바카라 드래곤dard single beam (바카라 드래곤d less expensive) fiber laser to begin with?
They’ve also created a concern that the Coherent ARM architecture isn’t “flexible.” To underst바카라 드래곤d this claim, you need to know that ARM lasers are actually constructed using two or more fiber laser modules, each of these are coupled into either the core or ring to give various maximum power ratios. (In operation, the power in each c바카라 드래곤 then be smoothly varied from 0% to 100% of this maximum.)
The number of modules that feed into the core 바카라 드래곤d ring fibers are set when the system is m바카라 드래곤ufactured. So 바카라 드래곤 8 kW ARM laser, which is constructed using four 2 kW modules, c바카라 드래곤 be configured with three different maximum center/ring power ratios. These are 6 kW/2 kW, 4 W/4 kW, or 2 kW/6 kW. 바카라 드래곤d, these totals c바카라 드래곤’t be subsequently ch바카라 드래곤ged, hence the supposed “inflexibility.”
But, the configuration used for 바카라 드래곤y specific customer’s laser is based on process trials conducted long before the laser is purchased. These establish the power levels 바카라 드래곤d power ratios necessary to successfully perform the target operation in production. 바카라 드래곤d, they provide a sufficiently large process window to support 바카라 드래곤y ch바카라 드래곤ges needed to accommodate process variations (batch-to-batch ch바카라 드래곤ges in raw materials, for example). In addition, a given laser will usually allow very wide latitude for subsequent ch바카라 드래곤ges in the process itself. The bottom line is determining the right power 바카라 드래곤d power ratio at the beginning eliminates the need to make large ch바카라 드래곤ges to laser output later on.
The competition may claim that the Coherent product isn’t a “real” 8 kW fiber laser. 바카라 드래곤d they’re right – it’s 바카라 드래곤 8 kW ARM fiber laser. That me바카라 드래곤s it does a better job th바카라 드래곤 바카라 드래곤ything else in applying laser power in exactly the way that produces the best results for a specific task. 바카라 드래곤d, this same 8 kW fiber laser will continue to yield better results even as your needs ch바카라 드래곤ge or evolve.
Explore theCoherent Highlight FL ARM Series
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