Comparison of Friction Stir Welding, Friction Surfacing and other ...

AKGEC INTERNATIONAL JOURNAL OF TECHNOLOGY, Vol. 4, No. 1
Comparison of Friction Stir Welding, Friction Surfacing and
other Welding Processes
Dr. M. Lakshmana Rao 1 , P. Suresh Babu 2 , Y. Seenaiah 3 and T. Rammohan 4
1
Department of Mechanical Engineering, Prakasam Engineering College, Kandukur 523105 AP.
2
Department of Mechanical Engineering, Rao & Naidu Engineering College, Ongole 523001 AP.
3
Department of Mechanical Engineering, RISE Prakasam School of Engineering, Vallur 523272 AP.
4
Department of Mechanical Engineering, Brilliant College of Engineering, Hyderabad AP.
1
lakshmanrao5@yahoo.com , 2 Sureshbabudevi.p@gmail.com, 3 seenaiah_yanamala@yahoo.co.in, 4 tocrm123@gmail.com
Abstract -- Friction stir Welding Process (FSW) is a solid state
welding method developed by The Welding Institute (TWI), and
now being increasingly used in the welding of Aluminum
including steels. FSW has now extended to variety of materials
including steels and polymers. Research towards the further
extension of the process to join dissimilar metal combinations
like Fe-Al and Al-Cu is currently underway. This paper highlights
the comparative study between FSW and Friction surfacing,other
joining processes. Hence this study may be helpful for enhancing
the welding quality. This study to be helpful for those who are
engaged in this area.
Keywords: Friction, Welding, Comparison, FSW, Quality, Properties,
Surfacing.
I. INTRODUCTION
FRICTION stir welding (FSW) process is an innovative
technique to join metals in the plasticity field, thus not reaching
the melting temperature and consequently the liquid state as it
happens in traditional welding processes. Friction stir welding
process has a wide application potential in ship building,
aerospace, automobile, and other manufacturing industries.
Friction stir welding is a relatively simple process as shown
in Fig.1.
A specially shaped tool, made from material that is harder and
wear resistant relative to the material being welded is rotated
and plunged into the abutting edges of the material parts to be
joined. After entry of the tool pin to almost the thickness of the
material the rotating tool is transitioned along the joint line to
enable the tool shoulder to just penetrate into the base metals.
As a consequence of the contact between the rotating tool
and the base metals, frictional heating of the material occurs.
This causes the base metals to plasticize and flow from the
front of the tool to the back where it cools and consolidates to
produce a high integrity weld, in the solid phase.
The quality of joints prepared by FSW process depend on a
number of variables including pin tool geometry, axial force,
rotational speed and traverse speed of the pin tool. This
necessitates a proper methodology for carrying out experiments
for identifying the appropriate values of these variables, and
for achieving the desired results in a shorter span as well as
with a minimum cost. Fig. 2 illustrates a flowchart showing the
methodology [4] for carrying out experimental investigations
in FSW process. During all these operations there are no
welding fumes, radiations, high voltage, liquid metals, or arcing,
and only few variables must be controlled. In fact a traditional
fusion welding depends up on several parameters like purge
Figure 1. Friction Stir Welding Process [1].
Figure 2. Flowchart showing the experimentation
methodology for FSW.
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COMPARISON OF WELDING PROCESSES
gas, voltage, amperage, wire feed, travel speed, shield gas and
arc gap, while the FSW process can be controlled with the
rotation speed, travel speed, pin tool pressure and eventually
other minor variables
II. COMPARISONS BETWEEN FSW & TIG
1) The formation of fine, equi-axed grains and uniformly
distributed very fine strengthening precipitates in the
weld region is the reason for superior tensile properties
of FSW joints compared to TIG joints [3].
2) The fractography of FSW joint revealed fine dimples
and TIG joint reveled course dimples, which shows that
FSW joints have higher ductility compared to TIG
joints[3].
the material is melted using conventional welding
techniques [4].
III. COMPARISION OF MATERIAL PROPERTIES
BETWEEN FSW AND OTHER PROCESSES
The tensile strength of the FSW joint is stronger than the MIG
joint, but lower than the base metal as seen in fig.3.The impact
strength of the FSW have more than the base metal and MIG
joint as seen in fig.4. The relative cost of the FSW joint is less
than the MIG joint shown in fig.5. Elongation of the FSW joint
is more than the MIG joint, but lower than the base metal as
seen in fig.6. The FSW process gives a fine microstructure,
while MIG welds have carse structure. Higher performance in
3) FSW joint exhibited higher strength values (51% of base
material) compared to TIG joint (44.5%) [3].
4) Micro hardness tests confirm the general decay of
mechanical properties induced by higher temperature
experienced by material in case of TIG joint [3].
5) Micro hardness tests performed in case of FSW joint
shows great differences among four different zones,
nugget zone, TMAZ (Thermo Mechanically Affected
Zone), HAZ (Heat Affected Zone) and base metal. The
first two zones are characterized by a general drop of
mechanical properties, even though nugget zone showed
a slight recovery due to fine grain structure [3].
Figure 3. UTS of Base Metal, FSW and MIG [4].
6) From industrial prospective, FSW is very competitive
because it saves energy due to less heat input, prevents
joints from fusion related defects, is cost effective and
has better strength than TIG joint [3].
7) FSW is an exciting process for welding pieces of material
together as receives little (or) no weld preparations,
operates at relatively low temperatures. So gives off no
fumes, is environmentally friendly, energy efficient and
can be used by only semi-skilled personnel to produce a
satisfactory weld. This process is suitable for welding
plate, pipe (or) fabrications and has been used to built
up components of complex shape [4].
Figure 4. Comparison of strength between
Base Metal, FSW and MIG [4].
8) As TIG and MIG welding processes replaced most of the
original stick welding operations in the past, it is
envisaged that FSW will displace many of the current
TIG (or) MIG welding applications with reduced costs
and superior weld quality [4].
9) As the welding is carried out below the melting point of
the material there is minimum heat affected zone with the
reduced ductility as observed with conventional
techniques. This can be particularly advantageous with
some aluminum alloys as segregation can occur when
Figure 5. Relative cost of FSW and MIG [4].
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AKGEC INTERNATIONAL JOURNAL OF TECHNOLOGY, Vol. 4, No. 1
The mechanism of bonding when mild steel is coated with
aluminum alloy as well as MMC is the formation of
intermettallics. Stainless steel coating of mild steel leads to
the formation of carbides in the stainless steel adjacent to the
interface as a result of carbon migration from mild steel towards
stainless steel [11].
Figure 6. Elongation of Base Metal, FSW and MIG [4].
production rate and quality as well as decreasing production
costs, can be obtained by FSW welding. They required preoperations
before the welding process are very limited in FSW.
This feature of the FSW process saves consumable material,
time cost and improves the quality of the welds [5].
IV. FRICTION SURFACING
Friction surfacing of the alloy was carried out using a
commercially available friction surfacing machine was
employed.The consumable was mounted on a holder that was
attached to the arbor of the machine.The substrate plate was
designed,cleaned and held in the vice,which is fixed on the
table of the drilling machine.Arbor is moved to the position of
the starting plate and is lowered down into position to deposit
the material on the starting plate.Once the loaded end of the
consumable is suffeciently hot(red hot),the arbor is moved
into position to deposit the materail on the substrate.The radial
drilling machine was set at a certain speed of rpm .The
translatory motion was manual .Once, the consumable was
suffeciently hot (red hot), and then the traverse feed was given
to the surfacing consuamble.The hot consumable material
flows plastically over the substrate to form a thick coating
process shown in Fig.7 [11].
Figure 7. Friction Surfacing.
IV. INDUSTRIAL SIGNIFICANCE
The potential significance of technology lies in its superiority
of retaining excellent mechanical and structural integrity of the
welds and its capability of being able to weld previously difficult
to weld materials, as well as welding of dissimilar metals.
Another emerging trend of this technology is the repair of
structural surfaces or repair of weldments, one of which is the
Friction Stir Processing (FSP) of materials as to enhance surface
characteristics and its mechanical properties [9].
V. CONCLUSION
1) Comparisons are shown between FSW and other
processes like TIG, MIG
2) From industrial prospective, FSW is very competitive
because it saves energy due to less heat input, prevents
joints from fusion related defects, is cost effective and
has better strength than TIG joint
3) Material properties are compared and shown between
FSW and Other processes.
4) Friction surface process is discussed
5) The potential significance of the technology lies in its
superiority of retaining excellent mechanical and
structural integrity of the welds and its capability of being
able to weld previously difficult to weld materials, as
well as welding dissimilar metals.
VI. REFERENCES
[1] A. Hartawan, T.B. Thoe, S.T. Ng, H. Wu and K.Liu, “Initial
Investigation in to Friction Stir Welding”, SIMTech Technical
Reports (STR_V10_N1-02-MTG) Vol. 10, No. 1, Jan-Mar
2009.
[2] V. Soundarrajan, M. Valant and R. Kovacevic, “An Overview
of R&D work in Friction Stir Welding at SMU”, Association
of Metallurgical Engineers of Serbia AMES,
UDC:669.141243.046.516-20.
[3] Ratnesh K. Shukla and Pavin K.Shah, “Comparative study of
Friction Stir Welding and Tungsten inert gas welding process”
Indian Journal of Science and Technology, Vol.3, No.6, June
2010.
[4] C.E.D Rowe et al. “Advances in Tooling Matreials for Friction
Stir Welding”, TWI and Cedar Metals Ltd. pp 1-11.
[5] Mustafa.K.K, Erdinc. Kaluc,Aydin Sic, “ Experimental
Investigation of MIG and Friction Stir Welding process of
Al(6061) alloy” The Arabian Journal for Science and
Engineering Vol. 35, No.1B, Apr 2010.
[6] J.A. Querin, H.A. Rubisoff and J.A. Schneider, “Pin Tool
Geometry Effects in Friction Stir Welding”. TWI (The Welding
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COMPARISON OF WELDING PROCESSES
Institute), pp 1-5.
[7] John Martin, “Materials for Engineering”, Second Edition,
WPL, Cambridge, England, 2002.
[8] Stefano Ferretti, DIEM, University of Bologona, “Friction
Stir Welding Process Optimization: Experimental Methods”,
International conference 2009, Bologona, pp 210-214.
[9] A.Hartawan, T.B.Thoe, S.T.Ng, H.Wu, and K.Liu “ Intitial
Investigation Into Friction Stir Welding” SIMTech Technical
Reports (STR_V10_N1_02_MTG) Jan-Mar 2009.
[10] Stefano Ferretti, “Friction Stir Welding process optimization:
Experimental methods” DIEM, University of Bologna Via
Risorgimento, 2-40136 Bologna.
[11] G. Madhusudan Reddy, ”Friction Surfacing of Metallic coatings
on steels”, Proc. Workshop on Friction Welding & Friction
Stir Welding, Nov.24-25, 2011. pp 5.1 -5.9
Prof Dr. M. Lakshman Rao is currently
Principal, Prakasam Engineering College,
Kandukur. Obtained BTech degree in
Mechanical engineering form S.K. University-
Ananthapur in 1994 and ME degree in
Production Engineering from MNNIT,
Allahabad in 1997. Conferred Doctorate (PhD
Mech.) by Osmania University, Hyderabad in
2010.
Seenaiah Yanamalamanda obtained BTech
degree in Mechanical Engineering from RVRJC
College of Engineering and MTech in
Production Engineering from SVU College of
Engineering.
Presently pursuing PhD research work at JNTU
Kakinada.
Published articles on welding in conferences
and journals. Has over 10 years experience in teaching.
C. Rama Moihana Rao studied graduation
(AMIE) from the Institution of Engineers and
Masters from JNTU, Hyderabad. His
specialization is Advanced Manufacturing
Systems.
He is currently working as an Associate
professor in Brilliant College of Engineering,
Hyderabad.
Pursuing PhD at JNTU, Hyderabad. Possesses teaching experience of
over 12 years.
Also completed Post Graduation in Computer
Science from JNTU, Kakinada in 2008. Specialized in the areas of
metal forming, welding, nano technology and composite materials.
Published 35 technical papers. Guiding 3 PhD scholars. He has abiding
passion for teaching and research. Received “Eminent Engineer Award”
on Sept 15th Engineers day for the year 2012 from the Institution of
Engineers India ,Vijayawada Chapter, A.P. Authored the book Operations
Research for Engineering Students. He is a life member of the Indian
Society for Technical Education.
P. Suresh Babu received his AMIE degree in
Mechanical Engineering from The Institution
of Engineers (India) in 1996, ME degree in
Metallurgical Engineering from PSG College
of Technology, affiliated to Bharathiar
University, Coimbatore, in 1998.
Currently pursuing PhD in Mechanical
Engineering at K.L. University, Vaddeswaram,
Guntur.
He has rich industrial and teaching experience of around 15 years in the
field of Mechanical and Metallurgical Engineering.
Published five technical papers. Currently working as Associate Professor
in Rao & Naidu Engineering College, Ongole, AP. His research interests
are in the areas of welding technology and metallurgy.
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