Unfortunately, holding a long arc makes it difficult to control the weld puddle, and becoming proficient can require weeks of training time. Pulsed MIG always held great promise, but older technology forced operators to hold a long arc length to avoid unintentional short circuits and arc re-strikes. Manufacturers developed new pulsed MIG welding systems to overcome operator training and acceptance issues. Most importantly, Alum-Line operators in both areas learned to weld with the new pulsed MIG technology after just a few hours of training. 1, Bead Comparison) and solved warping issues by reducing heat input. After switching to pulsed MIG, the operator increased travel speed by 30 percent, maintained good bead appearance (see Fig. 100- and 1/8-inch aluminum diamond plate. In another area, Alum-Line made long TIG welds on. ![]() The Profile Pulse feature is available on select Miller® equipment, including AlumaFeed®, Continuum™ and MPa+ feeder systems. The top image shows an AC TIG bead, while the bottom image shows a Profile Pulse™ bead. 1 - Bead comparison: Fabricators can substitute pulsed MIG for AC TIG on aluminum because it maintains bead aesthetics while increasing travel speeds and lowering heat input. A softer arc cone can help tie in both sides of the joint or the outside corner, while a stiffer arc provides good fusion at the root of the joint.įig. Using a simple function called arc control, operators can adjust the characteristics of the arc cone, which lets them tailor the arc to the application. Switching from AC TIG to pulsed MIG can increase travel speeds significantly while cutting heat input. The pulse of peak current provides the good fusion associated with spray transfer, while the low background current cools the weld puddle and lets it freeze slightly. How to prevent burn-through when MIG weldingįortunately, pulsed MIG technology is just right for welding thin aluminum. ![]() AC TIG, the process traditionally selected to weld thin aluminum, has the slowest travel speeds this increases cycle time and heat input, which makes the weldment prone to warping. Spray transfer MIG is too hot and prone to burn-through, especially on the back of the weldment or when gaps exist. Short-circuit MIG is too cool and subsequently prone to cold lap (aluminum’s excellent thermal conductivity transfers heat away from the weld area before good fusion can occur). Selecting a weld process for thin aluminum is like the story of Goldilocks tasting porridge. Causes of burn-through in welding aluminum While thicker sections of metal might not need advanced control, sheet metal offers little room for error, but lots of room for improvement. If you weld sheet metal and use conventional welding equipment, you know the challenges of welding this material - obtaining good fusion while simultaneously controlling:Īctivities that do not add value, such as grinding and rework
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