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

solidification cracking.

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

Ship Production

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.

9