Page 38 - MetalForming May 2015

Optimize Aluminum- Welding Performance
Critics of aluminum-weld quality don’t have to look very hard to find samples on which to place judgement. Their eyes rapidly fall on trailers, truck utility boxes, RVs, semi- trailer beds, emergency vehicles and pontoon and fishing boats, to name a few. In these and other aluminum applications, the weld beads stand naked to the world, begging critics to evaluate their profiles, perceived pen- etration and appearance. Critics with
Thom Burns is technical services direc- tor and Rob Krause is technical services manager, AlcoTec Wire Corp., Traverse City, MI, an Esab brand; www.alcotec.com.
managerial leanings also wonder about the cost of obtaining weld consistency and quality, as well as workforce-train- ing issues.
In the applications noted above, fabricators typically work with alu- minum sheet, plate and extrusions thinner than 3⁄8 in. This article provides advice for optimizing quality and pro- ductivity while lowering costs and sim- plifying training when welding thin aluminum products.
Advances in Pulsed GMAW
With the exception of procedures and codes that dictate using the GTAW (gas-tungsten-arc-welding) process,
The modified pulsed-spray transfer process enhances
weld-bead appearance, improves weld quality and
reduces filler-metal costs.
many aluminum components as thick as 3⁄8 in. can benefit from a welding process referred to as modified or advanced pulse-spray transfer. Based on the GMAW (gas-metal-arc-welding) process, this advanced pulse-spray process is available from several sup- pliers. While the technology behind each system varies, the end results are similar: the ability to obtain a uniform GTAW-like bead appearance without gun manipulation; the ability for the operator to use an advanced system without advanced process knowledge; and the ability to modify the distance between the weld-bead layers—what welders refer to as “stacked dimes.”
Here’s an introduction to modified pulsed-spray
transfer welding, and some valuable advice on how
to weld aluminum profitably.
BY THOM BURNS AND ROB KRAUSE
36 MetalForming/May 2015
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