ALL INDIA SHRI SHIVAJI MEMORIAL SOCIETY’S COLLEGE OF ENGINEERING, PUNE
A Seminar on
“FRICTION STIR WELDING”
GUIDED BY : Prof R!"#$%r! S T&'()
PREPARED PRE PARED BY: RAJ RAJESH ESH VA VADGAVE DGAVE
S)!* No T+-+./.0 TE T E Pro%'1*#o$ S!$%2#1& -+/3+4
INTRODUCTION :
Friction stir welding (FSW) was invented at The Welding Institute (TWI) of UK in 1991 as a solid state !oining techni"ue# and it was initiall$ a%%lied to aluminium allo$s& The 'asic conce%t of FSW is remara'l$ sim%le& A nonconsuma'le rotating tool with a s%eciall$ designed %in and shoulder is inserted into the a'utting edges of sheets or %lates to 'e !oined and traversed along the line of !oint&
Fig No. 01 Schematic drawing of friction stir welding
PRINCIPLE OF OPERATION :
A constantl$ rotated non consuma'le c$lindricalshouldered tool with a %rofiled %ro'e is transversel$ fed at a constant rate into a 'utt !oint 'etween two clam%ed %ieces of 'utted material& The %ro'e is slightl$ shorter than the weld de%th re"uired# with the tool shoulder riding ato% the wor surface&
Fig No. 02 Schematic diagram of the FSW process: (A) Two discrete metal work pieces !tted together" alo#g with the tool ( with a proe)
MICROSTRUCTURAL FEATURES :
The stir one (also nugget# d$namicall$ recr$stallised one) is a region of heavil$ deformed material that roughl$ corres%onds to the location of the %in during welding& The grains within the stir one are roughl$ e"uated and often an order of magnitude smaller than the grains in the %arent material& A uni"ue feature of the stir one is the common occurrence of several concentric rings which has 'een referred to as an *onionring* structure& The %recise origin of these rings has not 'een firml$ esta'lished# although variations in %article num'er densit$# grain sie and te+ture have all 'een suggested&
Fig ,o& -. The %rogress of the tool through the !oint# also showing the weld one and the region affected '$ the tool shoulder&
TOOL GEOMETRY :
Tool geometr$ is the most influential as%ect of %rocess develo%ment& The tool geometr$ %la$s a critical role in material flow and in turn governs the traverse rate at which FSW can 'e conducted&& An FSW tool consists of a shoulder and a %in as shown schematicall$ in Fig& As mentioned earlier# the tool has two %rimar$ functions
Fig& -/& Schematic drawing of the FSW tool&
TOOL GEOMETRY : The uniformit$ of microstructure and %ro%erties as well as %rocess loads are governed '$ the tool design& 0enerall$ a concave shoulder and threaded c$lindrical %ins are used&
Fig& -& WorlT2 and 23 TrifluteT2 tool
WELDING PARAMETERS : The rotation of tool results in stirring and mi+ing of material around the rotating %in and the translation of tool moves the stirred material from the front to the 'ac of the %in and finishes welding %rocess& 4owever# it should 'e noted that frictional cou%ling of tool surface with wor %iece is going to govern the heating&
Fig& -5& 6oint configurations for friction stir welding7 (a) s"uare 'utt# (') edge 'utt# (c) T 'utt !oint# (d) la% !oint# (e) multi%le la% !oint# (f) T la% !oint# and (g) fillet !oint&
PROPERTIES :
8esidual stress
4ardness
2echanical %ro%erties
orrosion 'ehaviour
2aterial s%ecific issues
o%%er allo$s
ADVANTAGES :
0ood mechanical %ro%erties in the aswelded condition
Im%roved safet$ due to the a'sence of to+ic fumes or the s%atter of molten material&
,o consuma'les : A threaded %in made of conventional tool steel&
;asil$ automated on sim%le milling machines : lower setu% costs and less training&
an o%erate in all %ositions (horiontal# vertical# etc&)# as there is no weld %ool&
0enerall$ good weld a%%earance and minimal thicness under
=ow environmental im%act&
DISADVANTAGES :
;+it hole left when tool is withdrawn&
=arge down forces re"uired with heav$dut$&
=ess fle+i'le than manual and arc %rocesses &
>ften slower traverse rate than some fusion welding techni"ues# although this ma$ 'e offset if fewer welding %asses are re"uired&
APPLICATIONS :
Aeros%ace
Shi%'uilding
Automotive
8ailwa$s
Fa'rication
8o'otics
?ersonal om%uters
SUMMARY AND FUTURE OUTLOO5: :
In these review article current develo%ments in %rocess modelling# microstructure and %ro%erties# material s%ecific issues# a%%lications of friction stir welding<%rocessing have 'een addressed&
Tool geometr$ is ver$ im%ortant factor for %roducing sound welds
4owever# at the %resent stage# tool designs are generall$ %ro%rietar$ to individual researchers and onl$ limited information is availa'le in o%en literature
From the o%en literature# it is nown that a c$lindrical threaded %in and concave shoulder are widel$ used welding tool features
CONCLUSION :
In this Seminar learn a'out various as%ects of Friction Stir Welding lie Tool geometr$# 2icrostructure etc& The 'asic conce%t of FSW is remara'l$ sim%le& A nonconsuma'le rotating tool with a s%eciall$ designed %in and shoulder is inserted into the a'utting edges of sheets or %lates to 'e !oined and traversed along the line of !oint&
The %ractical nowledge a'out %rocess is ac"uired&
REFERENCES :
8&S& 2ishra# @&& 2a# Friction stir welding and %rocessing# science direct 6ournal&
htt%s7<
www&sciencedirect&com
www&esa'na&com
Than ouCDDD
