Fiber laser welding is all about control of the process, according to Kurt Magedanz, laser process engineer at Ace Precision Machining Corp., Oconomowoc, Wis. With its new Laserdyne 430 systems, Ace Precision has made huge strides with weld quality while reducing operator intervention in the process.
Ace Precision Machining is AS9100 Certified and an internationally recognized supplier to the aerospace, power generation and defense industries, offering extensive manufacturing capabilities encompassing all areas of metal fabrication, joining and coating. It has experience with many turbine engine designs, including military platforms for Apache and Chinook Helicopters, Abrams M1 Battle Tanks, and B2, F18, F22 and F35 aircraft. The company’s laser welding capabilities recently took center stage when Ace Precision initiated a new welding process on one of its two recently acquired Laserdyne 430 fiber laser systems.
Growth of fiber laser welding is occurring rapidly. New processes pioneered by Prima Power Laserdyne, Champlin, Minn., and now adopted by Ace Precision, are part of that growth. Traditional welding methods, still prevalent in today’s manufacturing, require significant operator attention to control weld quality. With the power now available with a fiber laser and the proprietary integrated Prima Power Laserdyne S94P CNC control, change is underway.
“It’s all about the amount of control we have over the welding process now compared to before,” Magedanz said. “With the earlier process, we used a CO2 laser system that didn’t have weld-specific hardware or software. We experienced significant rework on the welded assemblies and needed to replace the laser lenses frequently. With only the most careful operator attention, we obtained acceptable weld quality up until Prima Power Laserdyne came forward with a greatly improved system and process.”
The challenging, two-part welded assembly that inspired this improved process was for a military application. With an approximate 12" (304.8 mm) diameter final assembly, the critical welding operation required a contoured, overlapping seam weld of a circular 0.060" (1.524-mm) thick Hastelloy X sheet metal part onto a machined Hastelloy X component. Keeping the weld seam consistent in width and depth without voids between the two parts was critical.
“With our new Laserdyne 430, the S94P laser processing camera system allows us to pinpoint the exact location of the weld seam on the Hastelloy X material. That allows us to fine-tune our position before the welding process begins,” reported Magedanz. He noted that with its old CO2 system, the component fit-up and fixturing were more critical to producing consistent welds. The new machine controller’s orbiting function, which oscillates (wobbles) the machine axes at a specific commanded size and frequency, allows for precise control of the characteristics of the weld joint.
“The new Laserdyne 430 fiber laser system has eliminated virtually all rework of parts that we used to encounter on the CO2 system, especially at the start/stop point of the weld,” he said. The particular configuration of the components that were welded places the weld bead close against the edge of the material with little margin for error to avoid burning the edge of the part. “The ability to precisely control the fiber laser’s power, position and focus, along with the system’s SmartRamp function, has made it possible and easier to control the laser welding process,” he said.
“Our previous welding process, with its combination of fixturing and assembly requirements, didn’t have enough precision to exactly pinpoint the true focus position repetitively,” said Magedanz. “The new OFC2 Absolute feature has superior mapping run-out with the new software, allowing for accurate and repeatable focus positioning.” This feature helps to precisely position focus on the weld joint of every part. Also, the OFC2 Absolute has a longer working range and is capable of measuring part surfaces on an angle regardless of the part surface condition. “This latest capability allows for a wider range of opportunities for improving existing processes,” Magedanz said.
Earlier, multi-process laser systems for cutting, drilling and welding were only just “adequate” for welding. According to Prima Power, its new Laserdyne 430s have new features designed for the challenges unique to welding as well as providing superior cutting and drilling. The systems feature weld ramping, gas flow control, lens protection and an integrated air knife that makes the welding process more controllable.
Ace Precision’s new Laserdyne 430 systems, OFC2 Absolute software feature provides better accuracy when it maps the weld surface. It does this to maintain the laser beam focus at the precise location of the laser weld so there is no deviation or voids in the weld structure. Also, OFC2 Absolute has a long working range so that the location of reference features such as edges, corners, holes, or other features can be determined using a greater, more generous stand-off between the laser processing head and workpiece providing no interruption of the process.
While the 20 kW laser on the Laserdyne 430 is most widely used for cutting and drilling, Prima Power Laserdyne’s proprietary software allows the laser to be effectively used for welding applications.
The BeamDirector feature provides two additional axes of motion to the moving table design for the Laserdyne 430. Precision welding comes not only from the performance and accuracy of the Laserdyne 430 motion system, but also from advanced Prima Power Laserdyne SmartTechniques that allow the fiber laser to effectively perform a full range of welding tasks, specifically Ace Precision’s complex welding of military components. This is the result of integrated control of the laser, motion and processors. Precision welding is not only measured by the accuracy and repeatability of the machine tool, but more importantly by the consistent parts produced on the system.
Both the capacitive and optical methods of focus control precisely guide the motion system, maintaining critical focus position and following the contour of the part regardless of surface irregularities. All linear axes of the system react to sensing of the part surface, creating unlimited correction along the axis of the beam. The combination of crash protection and part sensing gives the Ace Precision system operator confidence to use aggressive processing speeds possible without fear of damaging the system or scrapping the part.
“The weld head itself is another system feature we needed,” stated Magedanz. “We had limited lens protection with the CO2 system we were using. We’d complete two or three part runs and then need to replace the lens.” The latest Laserdyne 430 system, with an air knife feature incorporated in its SmartShield, blows air down and across the lens to keep it effectively free from weld spatter and debris while cooling the lens. The air knife creates an invisible barrier so contaminants are kept from depositing on the lens. With the SmartShield features, welding precision is ensured and costly lens replacement is minimized with the additional advantage of reducing machine downtime.
Looking to improve all of its laser operations at a busy time, Ace Precision also acquired a Prima Power Platino Fiber Evo laser system about the same time it acquired its two Laserdyne 430 fiber systems. The Platino gives Ace Precision increased performance for its flat sheet metal processing with reduced piercing times and increased cutting speeds, especially on thick material.
“Acquiring those three machines really helped make our laser operations more efficient and productive when we really needed it,” said Magedanz. “Prima Power is a leader with fiber laser technology and provides us with competitive advantages. Acquiring new fiber systems from the same manufacturer is efficient, cost effective and ensures a high level of service continuity that is important to us and our customers.”
Prima Power Laserdyne is a global developer and supplier of industrial precision laser processing systems for 3D welding, drilling, and cutting. Prima Power is also a system supplier of sheet metal cutting, bending and automated handling systems.
For more information from Prima Power Laserdyne, visit www.primapowerlaserdyne.com or call 763-433-3700.
For more information from Ace Precision Machining Corp., go to www.aceprecision.com or phone 262-252-4003.