Thesis Progress report

1. EXPERIMENTAL AND FE INVESTIGATIONS OF
FRICTION WELDING OF ALUMINUM TO
COPPER JOINTS
BY
REGASA MIDEKSA
DEPARTMENT OF PRODUCTION
ENGINEERING
DEFENCE UNIVERSITY
COLLEGE OF ENGINEERING

2. 1 INTRODUCTION
1.1 Background of the Study
Origin of joining processes can be tracked down to the past 2000 years,
but welding appeared in the 1800s. Welding is a fusion of two alike or
distinct materials fabricated together on account of heat generation. Due
to its portability and low-cost gas welding and arc welding were prevalent
welding techniques known in the twentieth century.
Later on, many other welding technologies have been emerged
out to prevail the drawbacks of traditional fusion welding such as
reduced material strength, distortion, and high levels of solidified
leftovers/ scraps.

3. CONT…
The joining of materials with different physical and chemical
properties on a permanent basis, with structural quality that meets
design requirements for applications in aerospace, aviation,
nuclear, military and automotive areas, has been a challenge for
engineering in the last years.
Friction welding is one of the solid state welding processes for
joining similar and dissimilar materials with good mechanical
properties and metallurgical bond such as hardness.
In friction welding of dissimilar materials, the input parameters
like the temperature generated in the bonding interface is directly
related with the weld strength and its interface properties.

4. CONT…
The non-uniform heat generation in the bonding interface generates
the formation of intermetallic compounds, unbold zones, and
insufficient plastic deformation to total removal of layers of oxides
and other contaminants in the bonding interface.
High temperature increases the intermetallic compound forming
and, consequently, the thickness of intermetallic layer that affects
the heat affected zone (HAZ).
1.2 Types of friction welding: Among those of different friction
welding (FW) techniques, the more interesting processes are:

5. CONT…
 Rotary friction welding (RFW): is a FW in which cylindrical
parts, typically rods or tubes, are placed in rotation with each
other and subjected to an axial compression load.
 Linear friction welding (LFW): the reciprocal linear
movement of one component relative to the other is applied to
produce heat.
 Friction stir welding (FSW) is a technique that involves
using an appropriate non-consumable stir tool for the
heating and mixing of the contact surfaces of metal sheets
to be welded.

6. CONT…
Fig.1.1: Rotary friction welding, Linear friction welding and Friction
stir welding respectively
Fig.1.2 welding process
Fig.1.3. Friction welded specimens

7. CONT…
Applications
Friction welding can be used to build better industrial rollers, tubes,
and shafts. The process is often used to manufacture these
subassemblies for industrial printers, material handling equipment, as
well as automotive, aerospace, marine, and oil applications.
Benefits
 FW is an eco-friendly process that doesn’t create smoke or release
other harmful toxins into the atmosphere.
 It offers a lot of control over the heat-affected zone, which reduces
change to material properties.

8. CONT...
 It also doesn’t require filler metal (which saves cost on raw
material).
 It offers simple automation, fast speeds, efficient welds, and the
ability to combine a variety of metals.
1.2 Statement of the problem
The light weight and cost effective materials having an optimum
quality with efficient performance is an increasingly demand in aero-
space and automotive industries. These materials are obtained by
joining different classes of materials; (metals with metals, metals with
their alloys, metals with composites, etc.).

9. CONT...
Specially, joining of the dissimilar materials such as Aluminum
(Al) and Copper (Cu) is of great demanding for industrial
applications. The need to join these materials is due to their having
well thermal and mechanical properties they possess, such as a
high corrosion resistance and a high electric conductivity.
However, as stated in the introductory part, the combination of
aluminum and copper is difficult for fusion welding. The
conventional welding methods result in the formation of
hard and brittle intermetallic phases at the interface of the
joint and the phases will eventually result in cracks.

10. CONT…
The use of Friction Welding (FW) to join two dissimilar materials
will result in an improved contact surface, improved current flow
and less resistance. These techniques show considerable
advantages when compared to traditional fusion welding
techniques, such as the absence of solidification defects, ability to
weld dissimilar materials, lack of consumables, and limited energy
requirements.
FW consumes little energy and no gas or flux is used, therefore
making the process environmentally friendly. Friction welding has
better technical and economical properties than conventional
welding methods.

11. CONT…
Friction welding is generally compared to electrical resistance
welding. However it can also be compared to other welding
methods such as electron beam welding and electrical arc
welding. One of the main advantages of friction welding is lower
energy requirement.
The FW technology produces high quality welds but to achieve
all these, there are several parameters that need to be addressed
during the welding process of materials.

12. CONT…
The welding process parameters, tool geometry, joint design and
heat generation exert a significant effect on the material flow pattern
and temperature distribution thus influencing the microstructural
evolution and the properties of the materials being welded.
The major problem with FW techniques is the formation of many
defects affecting the quality of the welded joint rising from plastic
deformation due to frictional heat that creates a bond between two
different dissimilar materials during the process. This study tries to
analyze the influencing parameters during FW of two dissimilar
materials.

13. CONT…
Hence, the process parameters should be carefully evaluated and
must be optimized with the commercially available software. In
this work, the Taguchi optimization technique will be used to
optimize the process parameters performed during FW.
1.3 Objectives of the study
1.3.1 General objective
The main objective of the research is to experimentally and FEM
investigate the effect of process parameters on the weld joint
performance of Al-Cu metals and thereby optimize the process
parameters for better joint quality.

14. 1.3.2 SPECIFIC OF OBJECTIVES:
 To prepare friction welding set up on vertical drilling machine;
 To conduct friction welding of Al and Cu metals for different
process parameters;
 To evaluate the effect of FW parameters namely upset pressure,
rotational speed (RPM) and friction time on the weld joint
performance (tensile strength, hardness, resistance);
 To determine optimum FW parameters using Taguchi method;
 To conduct FE simulation of the weld joint and then to verify the
optimal FW condition.

15. 1.4 SCOPE OF THE STUDY
In this thesis, an effort will be targeted to determine the causes for
defects that formulated during the FW for joining of aluminum to
aluminum (Al-Cu). This study will apply various appropriate
theoretical formulas and analytical calculations, by using criterion
experimental data which will be extracted from reviewed literatures
to get the right scientific decision. In addition to theoretical
calculation, the numerical simulations using ANSYS will be done
for validation of the work. Finally, the experimental validation will
be done.

16. 1.5 Expected outcome of the study
At the end of this thesis, one can expect that the full design of
an optimal process parameters are provided enabling joining of
especially bimetallic rods and also improving for tubular joints
by friction welding. The analyzed processes parameters
simulated by appropriate commercially available software and
experimentally validated results by Taguchi optimization
technique will be the output of this thesis. Comparison test
will be performed and finally an appropriate conclusions and
recommendations are to be drawn.

17. 1.6 Relevance of the proposed project in the context of current
status
Nowadays, the development of technologies are attempting on the
use of dissimilar materials joints due to their possession of
advanced mechanical, physical and thermal properties than that of
joints of similar materials. Thus, developing the technology of FW
will improve the weld ability of such materials and resulted in an
increased rate of production in automotive and aero-space
industries.

18. 2 LITERATURE REVIEW
2.1 Introduction
This chapter reviews different studies done on the joining of the
friction welding for different materials. As to be reviewed below, the
joining of different materials having different physical, chemical and
thermal properties have been done by different researchers. During
joining of such materials by Friction Welding method, a lot of
process parameters are affecting the joints quality. The following are
the researches done to optimize those parameters using different
optimization techniques.

19. CONT…
Title of the
literature
Author’s
Name and
Published
year
Findings
“Novel Optimization of
Friction Welding
Parameters to Improve
Mechanical Properties”
P, Pitchipoo, D.
Jebakani, and
Krishnaveni A.
2020.
They investigate on the FW between AISI
304 and aluminum alloy 6082-T6 and
studied the impact of various process
parameters with an experiment. They found
an optimum condition to be friction pressure
of 95.46 Pa, forging pressure 78.15 Pa,
friction time 4sec. and forging time 2sec.
“Characterizations of
Dissimilar Friction
Welding of ST37 and
CK60 Steels.”
Azizieh, M. et
al. 2016.
They conducted experiments on the friction
welded joints between MMC/AISI 304 stainless
steel. Finally they concluded that frictional
pressure and rotation speed have major impact on
the joint strength properties.

20. CONT…
Finite Element
Analysis of
Friction Welding
Process for 2024Al
Alloy and UNS
C23000 Brass
Srija, V.,
and A.
Chennakes
ava Reddy.
2015
They analyzed the optimum friction parameters on
joints between UNS C23000 Brass and 2024Al alloy
using FEA and Taguchi method to model the friction
welding process. The optimal conditions obtained were
frictional pressure (40 Mpa), (1500 RPM), frictional
time (4 sec) and upset pressure (37.5 Mpa).
Weldability
Analysis of 316
Stainless Steel and
AA1100 Alloy
Hollow Tubes
Using Rotational
Friction Welding
Process
Lekhana, Y
et al. 2015.
analyzed the weldablility of 316 stainless steel and AA1100
hollow tubes through friction welding process. They used
FEA and Taguchi design of experiments and found the
optimum conditions for frictional pressure of 80Mpa,
rotational speed of 2000 RPM, friction time of 5 seconds
and forging pressure of 160Mpa.
Joining of AISI
1040 Steel to 6082-
T6 Aluminum
Alloy by Friction
Welding
Muralimohan
, C.H et al.
2015.
They have studied the significance of process parameters on
the dissimilar welds between AISI 1040 and AA 6082-T6
aluminum rods by varying friction time, upset and friction
pressure while others kept are constant. They concluded that
upset pressure is more vital than the friction pressure and
the friction time.

21. Friction
Welding of
Steel to
Ceramic
Rombaut,
De Waele,
and Faes
2011
He gave a clear summary on the friction-welded joints
between steel and ceramics and observed results clearly by
adding of interlayer that was essential to reduce the residual
stresses and also to increase the strength of the friction welded
joints. He also observed that the intermetallic compound
(IMC) is another factor found to be influential on the bond
strength.
Effect of
Rotational
Speeds on the
Friction
Welding of
Alumina-
Aluminum
6061 Alloy
Joints
Uday M.
Basheer
Hasmaliza
M., Ahmad
Badri I.,
Ahmad
Fauzi M N.
2008.
He studied the impact of rotational speeds on the alumina-
6061 aluminum alloy rod joints through continuous drive
frictional welding. Varying rotational speeds, he concluded
that the Heat affected zone (HAZ), for welded joints at high
and low speeds of RPM was very thin and then the brittleness
nature of alumina couldn’t withstand resulting in failure and
furthermore showed cracks and un-joined regions. The joints
fabricated at medium RPM showed the presence of three
different regions and visibly a good joint was achieved.
Joining of AISI
1040 Steel to
6082-T6
Aluminum Alloy
by Friction
Welding
Muralimoha
n, C.H et al.
2015.
They have studied the significance of process parameters on
the dissimilar welds between AISI 1040 and AA 6082-T6
aluminum rods by varying friction time, upset and friction
pressure while others kept are constant. They concluded that
upset pressure is more vital than the friction pressure and the
friction time.

22. 2.1 SUMMARY OF THE LITERATURE REVIEW
Over the last many years as reviewed from the literatures, friction
welding had been investigated for analyzing of various mechanical
and heat properties of dissimilar materials on welding process by
using different FE codes like ANSYS, DEFORM (2D and 3D),
ABAQUS and CFD. But less work has been done for joining of tube
to tube or tube to rods specially aluminum and copper materials.
These materials are the most selective materials for making of tubes
and rods, and hence they are at the highest demanding in the
modern industries due to their best mechanical, thermal and
physical properties.

23. CONT…
But there are some difficulties for the joints during the process for
instance, Al and Cu have different melting point temperature of
(610°C and 1024°C) respectively and that affects quality of the
joints. Therefore, the fiction welding is an appropriate for joining
such dissimilar materials properly especially, for tubular joints and
hence, this study tries to focus on experimental and FE investigations
of friction welding of aluminum to copper joints to improve the
overall process parameters.

24. 3 RESEARCH METHODOLOGY
The methodologies that are going to be used are:-
3.1 Material requirements & their composition
Aluminum and Copper materials having dimensions [(10-20) mm
diameter, 0.5-15 mm thickness and of length 100mm] are selected due
to their good weldability, availability and applicability.
3.2 Machines & tooling requirements
 The specimens or components are to be mounted on the
conventional drilling machine,
 Setting up of all the welding equipment and parameters in
accordance with the welding procedure specification should be
performed.
3.3 Developing friction welding setup on vertical drilling machine
Experimental setup will be established using a conventional vertical
drilling machine because of availability and low cost.

25. CONT…
No extra setup is required for friction welding except tool and
fixture, so as to place piece in proper position during welding.
3.4 Tensile testing of welded joints:
After performing experiments, tensile strength is measured for the
purpose of determining the tensile yield strength and percentage of
yield elongation of friction welded joints of aluminium and copper.
3.5 Hardness testing:
Hardness testing will be measured with a standard hardness testing
machine since both metals used in the testing are soft metals. It will
be performed in the vertical position of the boundary friction welding
connection.
3.6 Resistance measurement techniques:
 Contact model, heat generation and heat input
Usually, contact in FW is considered to follow the conventional
Coulomb friction law, i.e., the shear stress of the contacting interface is
expressed as follows:

26. CONT…
τfric = μP (3.1)
where 𝜏𝑓𝑟𝑖𝑐 is the friction shear stress, µ the friction coefficient and P the
normal contact pressure. Hence, the heat generation from the friction is
described as follows:
qfric = ηγ τfric = ημPγ (3.2)
where qfric is the slipping rate, which may be dependent on the
relative position in different FW processes having various movement
forms, η the heat conversion efficiency.
For FW, the conventional Coulomb friction law will be only applied
at the very beginning of welding when the interface temperature is
relatively low. As the interface plasticized material is formed in larger
volumes at elevated temperatures, the friction behavior will be
dominated by visco-plastic friction.

27. CONT…
Therefore, heat generation is dependent on intense plastic deformation
of the thin shear layer at the interface. A modified Coulomb friction
law is then applied, where the equivalent flow stress of the material is
used as follows:
𝛕𝐟𝐫𝐢𝐜 = 𝛕𝐬𝐡𝐞𝐚𝐫 =
𝛔𝐬
𝟑
(3.3)
where 𝛕𝐬𝐡𝐞𝐚𝐫 is the flow shear stress calculated from the equivalent
flow stress 𝝈𝒔. Hence the heat generation (q) during FW could be
expressed as follow:
q = ηγmin (μP,
𝜎𝑠
3
) (3.4)

28. 3.7 TAGUCHI DESIGN OF EXPERIMENTS
Taguchi method is an efficient problem solving tool, which improve
the performance of the process, system, design and product with
significantly reduced experimental time and cost.
Taguchi suggested a specially designed method called the use of
orthogonal array to study the entire parameter space with lesser
number of experiments to be conducted.
Steps involved in Taguchi’s parameter design
a) Identify the main function and its side effects,
b) Identify the noise factors, testing condition and quality
characteristics,
c) Identify the objective function to be optimized,
d) Identify the control factors and their levels,

29. CONT…
e) Select a suitable Orthogonal Array and construct the Matrix,
f) Conduct the Matrix experiment,
g) Examine the data; predict the optimum control factor levels and its
performance,
h) Conduct the verification experiment,
 For this work, the Parameters like [upset pressure, rotational speed
(RPM) and friction time on the weld joint performance (tensile
strength, hardness, resistance) are to be investigated and hence
needed to be optimized to get the product with an improved
quality.
3.8 FE simulation of FW process
ANSYS workbench is one of well know commercial software which
is used for structural, Thermal, CFD analysis. ANSYS Wok bench is
well suited for this specific work, because it has a tremendous
selection of material, thermal and frictional contact properties.

30. 4 TIME AND BUGDET SECHDULE
4.1 Work Plan /Time Schedule
Table 4.1: Phase-I activities
No Activities 2021
April May June
1 2 3 4 1 2 3 4 1 2 3 4
1 Preparation of proposal
2
Submission of Formal written
proposal
3 Literature survey and data
collection
4 Phase 1 presentation

31. TABLE 4.2: PHASE-II ACTIVITIES
No Activities 2021
July August September October
1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
1 Analysing all the
process parameters
using ANSYS
2 Experimental validation
of parameters
3 Phase-II Presentation
4
Thesis writing and
editing
5 Thesis submission
6 Final presentation

32. 4.2 BUDGET SCHEDULE
Table 4.3: Estimated Materials Required and Budget for Thesis
No Items Specifications Unit Quantity Rate cost
birr
Total cost
birr
Diameter Length
1 Aluminium material 20 100 mm 1 500 500
2 Copper material 20 100 mm 1 550 550
3 Paper A-4 size Pack 1 220 220
4 pen Black Pack 1 200 120
5 Printing, photocopy,
and Binding cost
12 250 3000
6 Transport cost 3000
7 Software training 2000
8 Internet and RW CD 1000+100
9 Welding cost Available
Total cost 10,490

33. THANK
YOU !!!