Experimental Analysis to Optimize the Process Parameter of Friction Stir Welding of Aluminium Alloy(AA6082)

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072
© 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 1681
Experimental Analysis to Optimize the Process Parameter of Friction
Stir Welding of Aluminium Alloy(AA6082)
D.M. Nikam 1, N.V. Paithankar 2, A.S. More3 , A. B. Bansode 4, S.B. Deokar5
1BE Student, Mechanical, SND COE & RC, Yeola, Maharashtra, India
5Asst. Prof. Mechanical, SND COE & RC, Yeola, Maharashtra, India
---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - In many industrial applications steel is replaced
by non-ferrous alloys like aluminium alloys. Aluminium
alloys having good mechanical properties as compared to
structural steel and low weight it allows a significant
reduction in weight. But the welding of aluminium alloy by
conventional processes can causes serious problems. The
difficulties are like loss of alloying elements and presence of
the segregation and porosities in the weld joint. Friction stir
welding (FSW) is a solid state welding process, which
eliminates all theseproblemsofsolidificationassociatedwith
the traditional fusion welding processes.
In this research work the attempt has been made to develop
an empirical relationship between FSW variables (tool
rotation, tilt angle and welding speed) and tensile strength
and yield strength of single pass and multi pass friction stir
welded aluminium alloy 6082 butt joints. Taguchi method
and particle swarm optimization technique was adopted for
the analysing the problem in which several independent
variables influence the response. Three-factors three level
central compositedesign wasused to findtheoptimalfactors
of friction stir welding process for aluminium alloy.
Index Term: Design of experiment, Frictionstirwelding,
Taguchi method.
1. INTRODUCTION
In today’s modern world there are various welding
techniques to join metals. They range from the conventional
oxyacetylene torch welding to the laser welding. The two
types of welding can be separated as fusion welding and
pressure welding. The fusion welding istheprocessinvolves
bonding of the metal in the molten stage and may need a
filler material if required such as a unpreserved electrodeor
a spool of wire. Some processes may also need an inert
ambience in order to avoid corrosion of the molten metal. A
flux material or an inert gas shield in the weld zone protects
weld pool to avoid defects. Examples of fusion welding are
metal inert gas welding (MIG), tungsten inert gas welding
(TIG) and laser welding. There are a lot of disadvantages in
the welding techniques where the metal is required to melt.
Temperatures and let it the harden to form the joint. The
melting and solidification causes the mechanical properties
of the weld in some cases to get worse such as low tensile
strength, fatigue strength and ductility. The disadvantages
also include porosity, oxidation, micro segregation, hot
cracking and other microstructure defects in the joint. The
process also limits the combination of the metals that that
can be joined because of the different thermal coefficientsof
expansion.
From the literature surveythevariousmaterial ofaluminum
serious is tested but the aluminum alloy of6082isremain so
I selected this material.
1.1 NEED OF FRICTION STIR WELDING
More than 100, 00,000 workers in the world are currently
employed full time as welders, while higher number of
workers performs welding intermittentlyaspartoftheir job.
A number of epidemiologic studies have reported a higher
incidence of respiratory ill health in welders. Respiratory
effects observed in full-time welders have included
bronchitis, airway irritation, metal fume fever, chemical
pneumonitis, lung infection changes, and a possibleincrease
in the incidence of lung cancer. It is important to reduce
welding fume toxicity and exposure whenever possible.
Jayaraman states the effect of friction stir welding process
parameters on tensile strength of cast LM6 aluminum alloy
also the quality of weld zone was investigated using
macrostructure and microstructureanalysis.Theyproposed
that about the 12 joints fabricated, that the joint made-up
using the process parameters of 900 r/min (tool rotation
speed), 74 mm/min (welding speed) and 3 KN and (axial
force) yielded higher tensile strength compared to other
joints.
1.2 METHODOLOGY
For the welding purpose the plates of aluminum AA6082
were prepared then these plates were welded by using a
square profile tool with single pass and double pass. The
specimens were prepared and tested on universal testing
machine. The obtained results of the tensile strength were
optimized by using the optimization techniques like
ANNOVA and PSO. Thus optimum values were found.The
flow chart given below represents the methodology for the
project. Friction Stir Weldingis a simple processinwhichthe
rotating cylindrical tool with a shoulder and a profiled pin is
plunged into the plates to be joined and traversed along the
line of the joint. The plates are tightly clamped on the bed of

the FSW equipment to prevent them from coming apart
during weld.
Fig.1: Flowchart for Actual Process to be carried out
during FSW
A cylindrical tool rotating at high speed is gradually plunged
into the platematerial, until the shoulderofthetooltouchthe
upper surface of the material. A downward force that is
applied to maintain the contact. Frictional heat, generated
between a tool and the material, causes that the plasticized
material to get heated and softened, without reaching the
melting point. The tool is then traverse along with the joint
line, until it reaches the end of the weld.
As the tool is then moved in the direction of welding, the
leading edge of the tool that forces the plasticized material,
on either side of the line, to the back of the tool. In effect, the
transferred material is forged by that the close contact of the
shoulder and the pin profile. In order to achievethecomplete
through thickness welding, the length of the pin should be
slightly less than a plate thickness, since only limitedamount
of deformation occurs below the pin. The tool is generally
tilted by 2 to 4°, to facilitate better consolidation of the
material in the weld.
Fig.2: Schematic representation of FSW process
and tool profile
1.3 EXPERIMENTAL METHOD
1.3.1. Design of Experiments
Design of experiments is a methodofdesigningexperiments,
in which only selected number of experiments are to be
performed. For example if there are three parameters with
three levels of each parameter, then the total number of
experiments to be performed is 33= 27 experiments. But
using design of experiments method, only 9 experimentsare
needed to be performed. On thebasisofthese9experiments,
the significance and optimal levels of each parameter is
obtained. According to the L9 orthogonal array, 3
experiments in each set of process parameters have been
performed on IS 3039 plates. The 3 factors used in this
experiment are the rotating speed, tool tilt angle and travel
speed. The experiment notation is also included in the L9
orthogonal array which results in an on additionalcolumn,in
order to represent the parameters. The experiments are
performed on the vertical milling machine which serves to
perform the FSW operation. It is a well-known factor that at
higher rotating speed, FSW produces high heat input and
these 3 levels were selected as low, medium and high speed
among the highest speeds available in the machine. Only at
low travel speeds, the weld could be achieved with a shorter
pin and hence the 3 least travel speeds were taken. Beyond
the tool tilt angle of 2° the pin pierces out the plasticized
material for the thickness of 3mm plate, and hence 0°, 1° and
2° tool tiltanglesweretaken.Thevariousprocessparameters
are as follows.
A. FIXED PARAMETERS
1. Force
2. Shoulder plunger
3. Penetration ligament
4. Tool pin profile
B. VARIABLE PARAMETERS
1. Tilt angle
2. Rotational speed
3. Welding speed.
1.4 TOOL DESIGN
Tool introduction
According to K.Ramanjaneyulu, G. Madhusudhan Reddy, A.
Venugopal Rao, and R. Markandeya, Experiment was
conducted with different tool pin profiles are (conical,
triangular, square, pentagon, and hexagon cross sections)
maintain that the same swept volume during the tool
rotation. The pin-to-swept volume ratio varies due to

changes in the physical volume of the pin only. In other
words, the pin-to-swept volume ratio varies due to changes
in the physical volume of the pin only.
In our project work we had studied various papers
and finally we have selected hexagonal.
Fig.3: Square tool profile
1.5 WORK PIECE MATERIAL AA 6082-T6
Aluminum alloy 6082 is a medium strength alloy with good
corrosion resistance. It has the highest strength of the 6000
series alloys. Alloy 6082 is known as a structural alloy.
Typical composition limits are shown in Table No. 1. In plate
form, 6082 is the alloy most commonly used for machining.
As a relatively new alloy, thehigherstrengthof6082hasseen
it replace 6061 in many applications. Theadditionof amount
of manganese controls the grain structure which in turn
results in a stronger alloy. It is difficult to produce thin
walled, complicated extrusion shapes in AA6082. The
extruded surface finish is not as smooth as other similar
strength alloys in the 6000 series.
Fig.4: Workpiece material
In this investigation, the base materials,Al 6082-T6,whichis
a precipitation hardened aluminum alloy widely used in
aerospace applications due to its high strength was used.
FSW plates are examined using spectrometer. Table shows
the mechanical properties of base metal AA 6082.
Table -1: Sample Table format
Elemen
t
Si Fe Cu M
n
Mg Cr Ni Zn
Compos
ition in
%
0.
75
0.1
8
0.
01
0.
4
0.42 0.0
1
<0.0
05
0.
01
Elemen
t
Ti Pb Sn V Zr Sr Al
Compos
ition in
%
0.
02
<0.
05
0.
01
0.
01
<0.0
05
<0.
01
98.1
Table -2: Mechanical Properties of Base Metal AA6082
Material Hardness(HV) Ultimate
Strength(MPa)
%
Elongation
AA6082 95 250 10
Plate of size 160x20x5 mm is selected for testing of tensile
strength on universal testing machine. The aim for
machining both sides of the plates is to make them parallel
for the FSW machine clamping system. The parallel plates
enabled the uniformity in welding the gaps between the
plates.
1.6 MATERIAL SELECTION OF TOOL FOR FRICTION
STIR WELDING
Friction stirring is the thermo mechanical deformation
process where the tool temperature approaches the solidus
temperature of base metal. Production of a quality friction
stir weld requires the proper tool material selection for the
desired application. Naturally, there are important effects to
the tool during welding: abrasive wear, high temperature
and dynamic effects.
The following characteristics have to be considered for
material choice,
1. Ambient and elevated temperature strength,
2. Elevated temperature stability,
3. Wear resistance,
4. Coefficient of thermal expansion,
5. Machinability
There are several tool materials to use depending on the
base material:
1. Hot-work tool steels: the most commonlyusedmaterial,
easy availability and Machinability, wear resistance,
especially for aluminum and copper.
2. Nickel- and cobalt base alloys: high strength, excellent
ductility, hardness stability, these alloys derive their
strength from precipitates, so the operational
temperature must be kept below the precipitation
temperature (typically 600 – 800 °C).
3. Refractory metals (W, Mo): high temperature strength,
strongest alloys between 1000 – 1500 °C, expensive,
difficult machining.
4. Tungsten-base alloys: good strength, high operational
temperature, high cost (W-Re).

Carbide particle reinforced metal composites (WC, WC-Co,
and TiC): superior wear resistance, reasonable fracture
toughness.
ACKNOWLEDGEMENT
We feel great pleasure to present the Dissertation
entitled“Experimental Analysis to Optimize the Process
Parameter of Friction Stir Welding of Aluminium Alloy
(AA6082)”. But it would be unfair on our part if we do not
acknowledge efforts of some of the people without the
support of whom, this dissertation work would not have
been a success.
First and for most we are very much thankful to our
respected Guide Prof. Deokar.S.Bforhisleadingguidancein
this dissertation work. Also he has been persistent source of
inspiration to us. We would like to express our sincere
thanks and appreciation to Prof. Bhamre V.G. (HOD) for
valuable support. Most importantlywewouldliketo express
our sincere gratitude towards our Friends & Family for
always being there when we needed them most
REFERENCES
[1] M. Jayaraman, R. Sivasubramanianand, V.
Balasubramanian, “Effect of Process Parameters on
Tensile Strength of Friction Stir Welded Cast LM6
Aluminum Alloy Joints” Vol.25 No.5, (2009).
[2] A. K. Hussain and S. A. P. Quadri, “Evaluation of
Parameters of Friction Stir Welding For Aluminum
AL6351 Alloy”, International Journal of Engineering
Science and Technology, Vol. 2, (2010).
[3] K. Ramanjaneyulu, G. Madhusudhan Reddy, A.
VenugopalRao, and R. Markandeya,“Structure-Property
Correlation of AA2014 Friction Stir Welds: Role of Tool
Pin Profile”, ASM International, MEPEG 22:2224–
2240(2013).
[4] B.T. Gibson, D.H. Lammlein, W.R. Longhurst, C.D. Cox,
M.C. Ballun, K.J. Dharmaraj, G.E. Cook, A.M. Strauss,
Journal of Manufacturing Processes 16 56–73(2014).
[5] A. Pradeep, S. Muthukumaran, “An analysis to optimize
process parameters of friction stir welded low alloy
steel plates”, International Journal of Engineering,
Science and Technology Vol. 5, No. 3, pp. 25-35, 2013.
[6] Shrikant G. Dalu, M. T. Shete, “Effect of Process
Parameters on Friction Stir Welded Joint: A Review”,
IJRET: International Journal of Research in Engineering
and Technology eISSN: 2319-1163 | pISSN: 2321-7308
[7] H.S Patil, S.N.Soman “Experimental study on effect
welding sped tool pin profile on aluminiumalloy”IJRET:
International Journal of Research in Engineering and
Technology Vol 2, No.5, 2010,pp 268-275.
[8] Ahmed KhalidHussain,Syed AzamQuadri”Evolutionof
parameters of friction stir welding for Aluminium AA
6351 alloy “ International journal Science and
technology vol No.2(10)2010,pp 5977-5984.
[9] DawesC.WayneT.,“Frictionstirjoiningofaluminiu
malloys”,TWIBulletin,No.6,1995.
[10] ThomasW.M.et“FrictionStirButtWelding”,Interna
tionalpatentAppl.No.PCT/GB92/02203,GBpatentApp
l.No.9125978.8andU.S. Patent No.5, 460, 317, 199.
BIOGRAPHIES
Dattatray M. Nikam, SND COE
Yeola, Pune University,
Department of Mechanical
Engineering.
Nitin V. Paithankar, SND COE
Engineering.
Akshay S. More, SND COE
Engineering.
Abhijit B. Bansode, SND COE
Engineering.
Prof. Sagar B. Deokar, SND COE
Engineering.
.

Experimental Analysis to Optimize the Process Parameter of Friction Stir Welding of Aluminium Alloy(AA6082)

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