Solid State Friction Stir Welding
allows the plug material and previously welded
materials to fuse together. With this process, no
Solid State Friction Stir Welding produces a stron
external materials are used.
ger and more reliable weld than other types of weld
UFSWS also allows welding of diverse material,
ing operations. This welding operation also reduces
increases fatigue resistance by up to 30%, improves
and eliminates the need for consumable welding ma
ductility, prevents fumes, ensures safe operation,
terials, and reduces hazardous fumes.
reduces weld defects, welds tapered thickness joints,
and reduces and eliminates the need for external
The National Center for Advanced Manufactur
materials. UFSWS also eliminates porosity and
ing (NCAM), in a joint venture with the state of
Louisiana, the National Aeronautics and Space Ad
ministration (NASA), the University of New Or
Use of LIght Detection and Ranging for
leans, and Lockheed Martin Space Systems Com
pany Michoud Operations, researched the
application of the Universal Friction Stir Welding
System (UFSWS). The system eliminates the need
The University of New Orleans, College of Engi
for consumable welding products and increases the
neering has been conducting research on the use of
strength of the welded surfaces. Present technol
LIght Detection and Ranging for ship production.
ogy allows only the welding of one side of two metal
items at a time. For both sides to be welded, two
The University of New Orleans, College of
passes must be performed. Furthermore, an exter
Engineering s (UNO COE s) Gulf Coast Region Mari
nal material must be used to join the two items (i.e.,
time Technology Center (GCRMTC) conducted re
welding rods), and when joining two metal surfaces,
search on the use of LIight Detection and Ranging
gases are expended.
(LIDAR) for ship production. The LIDAR system is
UFSWS is performed by the use of a pin tool that
a unique technology in that it can take a three di
rotates at a speed causing the metal to plasticize.
mensional scan of an object through multiple scans.
Two types of pin tools are used. First, a retractable
This system can be used to determine the accuracy
pin tool, approximately the thickness of the mate
and quality of as built modules and complete ves
rial being welded, rotates at a speed allowing the
sels to greatly speed and improve the manufactur
pin tool to penetrate the two units to be welded.
ing process. It can also be used to obtain as built
The tool is pressed down into the two units until
drawings, and perform reverse engineering on as
the pin tool s shoulder impacts the two surfaces.
built sub systems.
Once the shoulder contacts the surfaces, the rotat
GCRMTC determined that the Riegl LPM 25HA C
ing pin tool will generate enough frictional heat to
LIDAR as one system that is suitable to the ship
plasticize the metal edges. When this occurs, the
yard production environment based on range, data
pin tool traverses along the weld seam and plasti
collection rate, accuracy, and eye safety. Acquir
cizes the metal generating a combination of extru
ing multiple scans of an object from different views
sion and forging. After the tool moves away from
is needed because LIDAR scanners can only cap
the plasticized metal, it solidifies to become solidly
ture data from one perspective. PolyWorks and
welded yielding a ductile, high strength, solid state
MENSI 3Dipsos 2.4c software is being used to com
weld. The second pin tool is self reacting where a
bine scans to form one point cloud and produce 3D
hole is drilled between the two items to be welded.
models and conventional 2D drawings. The accu
The self reacting pin tool has two shoulders that
racy of two mating assemblies that are to be fit
impact the front and back of the items being welded
ted can be determined using PolyWorks IMAlign
and a pin that goes through them. In a similar pro
software. The alignment error as a function of
cess, as is performed with the retractable pin tool,
position is graphically represented. The alignment
the metal edges are plasticized, mixed together, and
error can then be corrected.
re solidified. This operation allows the pin tool to
Interior and exterior measurements of a ship or a
weld the full thickness of the metal being welded,
building and numerous other shipyard applications
which ensures welding on both faces at the same
can be easily acquired through LIDAR. GCRMTC
time. At the end of this process, only a hole is left to
plans to introduce and train the shipbuilding indus
plug. A special plug has been manufactured that
try on the use of LIDAR.