More Applications Ahead
The best candidates for FSW are long,
longitudinal weld configurations in
butt, lap, combination butt/lap, and
fillet joints on aluminum. All light
metals, including aluminum alloys,
copper alloys, magnesium, zinc, and
lead, can be industrially friction stir
welded. A number of high-melting-temperature alloys are also successfully joined using FSW (see Figure 6).
As aluminum is used more commonly in transport vehicles like trucks
and trailers to reduce the “dead-load”
and increase the payload, and as environmental concerns call for reduced
weight in many road applications,
FS W is a good production option. With
many straight linear welds and easily weldable materials in thicknesses
typically up to 0.20 in. ( 5 mm), truck
components are ideal for the process.
Transportation applications also
include telescopic lift booms. Made of
four 7000 series profiles, the booms
are 28 ft. ( 8. 5 m) long, have a thickness range of 0.20 to 0.39 in. ( 5 to 10
mm), and are welded at speeds up to
3. 3 FPM (1 m/min).
Automotive applications with large
manufacturing batches, Six Sigma requirements, and challenging material
combinations such as aluminum and
magnesium alloys are a suitable fit for
FSW. In one such application, welding
seat frames, FSW cycle time was less
than one minute per seat using dual
Electronic devices can benefit
from FSW as well. In one example, a
loudspeaker frame made of cast aluminum is friction stir welded. This
results in no heat-induced deformations in the final product and a solid
structure with good acoustics.
In another example, FSW played a
key part in the redesign of a cooling
block for a heavy-duty cutting machine. Instead of using one large extrusion, the new design friction stir welds
together two profiles to form one structure for a more cost-effective production method. The penetration on the
weld is approximately 0.60 in. ( 15 mm).
In the energy industry, orbital FSW
is used to create welds for land and
offshore pipelines. FS W of up to 0.5-in.
( 12.7-mm) maximum on X65 through
X100 steels is highly repeatable. The
process is much more energy-effi-cient than arc or laser welding, so energy consumption can be reduced by
60 percent to 80 percent.
Copper canisters for spent nuclear fuel are sealed successfully using FSW. The challenges in welding thick copper are high welding temperatures up to 1,743 degrees F,
high welding forces, and the duration of the weld (up to
one hour). FSW is able to address these severe demands.
Virtually anywhere aerospace or civil aviation equip-
ment is being manufactured, FSW production technology
is being considered for future designs, including those for
carrier beams, floors, and complete fuselages and wings.
Boeing has used the technology to manufacture rocket
fuel tanks. Production time for a typical tank is reduced
dramatically and a number of cost savings achieved, espe-
cially when compared to the cost of riveting.
A next step for FSW is joining of superplastically formed
products. Applications include manufacturing automotive
door components. In superplastic forming, pressurized gas
is used to impart the product’s final shapes.
As new areas are explored, more applications are proving suitable for this cold weld process.
Martin Brennan is welding automation sales manager, ESAB
Welding & Cutting Products, 411 S. Ebenezer Road, Florence, SC
29501, 843-669-4411, email@example.com, www.esabna.com.