Page 33 - MetalForming August 2019

5Five Tips for Better Aluminum GMAW
These recommendations help control heat input, optimize results and reduce rework when welding aluminum sheet metal.
BY KODI WELCH
Lightweight, easy to form and But joining aluminum sheet—for input and makes it easier to weld thin
resistant to rust, aluminum sheet
metal offers manufacturers the option of skipping the painting step when producing parts. These benefits make the material popular in a range of applications, from toolboxes and jon boats to signs and awnings.
Kodi Welch is senior welding engineer/ CWI and application specialist, Miller Electric Mfg. LLC, www.millerwelds.com; and Galen White is senior welding engi- neer and product specialist for Hobart Welders, www.hobartwelders.com.
the purposes of this article, sheet meas- ures 0.125 in. thick or less—via gas metal arc welding (GMAW ) presents some challenges, as operators must take care to avoid warpage, distortion and burnthrough. The following five tips will help operators better control heat input and improve their tech- niques, thus optimizing results and reducing rework.
1 Use pulsed GMAW welding. The right welding process helps improve results. For example, pulsed GMAW lowers the heat
materials and minimize burnthrough. This welding process alternates between a high peak current and a lower background current, which low- ers overall amperage. The pulse of peak current propels the molten droplet across the arc and provides the energy to produce good fusion associated with spray transfer, while the low back- ground current allows the weld puddle to cool.
Pulsed GMAW also allows operators to run larger-diameter wire at lower cur- rents than needed to run a non-pulsed
www.metalformingmagazine.com
MetalForming/August 2019 31
FABRICATION