Post on 18-Jan-2021
FACULTY OF ENGINEERING, CAIRO UNIVERSITY
GIZA, EGYPT
2017
EFFECT OF FRICTION STIR WELDING PARAMTERS ON THE
PEAK TEMPERATURE AND THE MECHANICAL PROPERTIES
OF AA5083-O
By
Mostafa Mohamed El_Sayed Abd El_Aleem
A Thesis Submitted to the Faculty of Engineering at Cairo University in
Partial Fulfillment of the Requirements for the Degree of
MASTER OF SCIENCE
In Mechanical Design and Production Engineering
FACULTY OF ENGINEERING, CAIRO UNIVERSITY
GIZA, EGYPT
2017
EFFECT OF FRICTION STIR WELDING PARAMTERS ON THE
PEAK TEMPERATURE AND THE MECHANICAL PROPERTIES
OF AA5083-O
By
Mostafa Mohamed El_Sayed Abd El_Aleem
A Thesis Submitted to the Faculty of Engineering at Cairo University in
Partial Fulfillment of the Requirements for the Degree of
MASTER OF SCIENCE
In Mechanical Design and Production Engineering
Under the Supervision of
Dr. Mahmoud Mohamed Abd-Rabou
Dr. Ahmed Yehia Shash
Professor, Mechanical Design and
Production Engineering Department
Faculty of Engineering, Cairo University
Assistant Professor, Mechanical Design and
Production Engineering Department
Faculty of Engineering, Cairo University
FACULTY OF ENGINEERING, CAIRO UNIVERSITY
GIZA, EGYPT
2017
EFFECT OF FRICTION STIR WELDING PARAMTERS ON THE
PEAK TEMPERATURE AND THE MECHANICAL PROPERTIES
OF AA5083-O
By
Mostafa Mohamed El_Sayed Abd El_Aleem
A Thesis Submitted to the Faculty of Engineering at Cairo University in
Partial Fulfillment of the Requirements for the Degree of
MASTER OF SCIENCE
In Mechanical Design and Production Engineering
Approved by the Examining Committee
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Prof. Dr. Mahmoud Mohamed Abd-Rabou (Thesis Main Advisor)
Professor, Mechanical Design and Production Engineering Department, Faculty of
Engineering, Cairo University
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Prof. Dr. Tarek Mahmoud El-Hossainy (Internal Examiner)
Professor of Mechanical Design and Production Engineering Department, Faculty of
Engineering, Cairo University
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Prof. Dr. Tamer Samir Mahmoud (External Examiner)
Professor of Mechanical Design and Production Engineering Department, Faculty of
Engineering at Shoubra, Benha University
Engineer’s Name: Mostafa Mohamed El_Sayed Abd El_Aleem
Date of Birth: 6/ 11 /1987
Nationality: Egyptian
E-mail: MostafaMohammed30@yahoo.com
Phone: 01112429062
Address: 24Suobhi Ewis st, Shoubra ElKhiema, Kalubia
Registration Date: 1/10/2012
Awarding Date: 2017
Degree: Master of Science
Department: Mechanical Design and Production Engineering
Supervisors:
Prof. Dr. Mahmoud Mohamed Abd-Rabou
Dr. Ahmed Yehia Shash
Examiners:
Prof. Dr. Mahmoud Abd-Rabou (Thesis Main Advisor)
Prof. Dr. Tarek El_Hossainy (Internal Examiner)
Prof. Dr. Tamer Samir (External Examiner)
Title of Thesis:
EFFECT OF FRICTION STIR WELDING PARAMTERS ON THE
PEAK TEMPERATURE AND THE MECHANICAL PROPERTIES
OF AA5083-O
Keywords:
Friction stir welding; Finite element Method; Modeling and simulation; Mechanical
properties; Tool pin profile
Summary:
This research aims to investigate the temperature distribution during FSW process of
AA5083-O numerically and experimentally. Moreover, the residual thermal stresses are
predicted by using Abaqus Finite Element Analysis program. AA5083-O plates were
friction stir welded at different conditions by variation of tool pin profile, rotational and
welding speeds. Furthermore, macrostructure, microstructure evolutions, hardness and
tensile strength examinations were performed on each friction stir welded joint.
i
Acknowledgments
Firstly, I would like to express my sincere gratitude to my advisors Prof. Dr. Mahmoud
Abd-Rabou and Dr. Ahmed Shash for the continuous support of my master study and
related research, their patience, motivation, and immense knowledge. The author is also
acknowledging Dr. Mohamed Zaki, Metallurgical and Materials Engineering
Department, Faculty of Petroleum and Mining Engineering, Suez University. The
author would like to extend his thanks to everybody in Arab Organization for
Industrialization and Arab Contractors for their support in implementing the practical
work and tests.
ii
Dedication
To my parents, my wife and my daughters
iii
Table of Contents
ACKNOWLEDGMENTS I
DEDICATION II
TABLE OF CONTENTS III
LIST OF TABLES VI
LIST OF FIGURES VII
NOMENCLATURE XI
ABSTRACT XII
CHAPTER 1 : INTRODUCTION 1
CHAPTER 2 : LITERATURE REVIEW 3
2.1 FRICTION STIR WELDING PROCESS (FSW) 3
2.1.1 OPERATION PRINCIPAL OF FSW PROCESS
3
2 .1.2 ADVANTAGES AND DISADVANTAGES OF FSW FOR ALUMINUM
JOINING
4
2.1.3 FSW APPLICATIONS 5
2.1.4 FRICTION STIR WELDING PROCESS PARAMETERS 6
2.1.5 MICROSTRUCTURE OF FRICTION STIR WELDED ALUMINUM JOINTS 10
2.1.6 MECHANICAL PROPERTIES OF FRICTION STIR WELDED ALUMINUM
JOINTS
14
2.1.7 HEAT GENERATION DURING FRICTION STIR WELDING PROCESS 22
iv
2.1.8 FINITE ELEMENT MODELING OF FRICTION STIR WELDING 23
2.2 SUMMARY
26
CHAPTER: 3 FINITE ELEMENT MODELING AND EXPERIMENTAL
INVESTIGATION
27
3.1 SCOPE OF RESEARCH 27
3.2 FINITE ELEMENT MODELING
29
3.2.1 IDEALIZATION
29
3.3 EXPERIMENTAL INVESTIGATION
35
3.3.1 TOOL DESIGN
35
3.3.2 WORK PIECE DESIGN 36
3.3.3 MACHINE SET UP AND OPERATION CONDITIONS 37
3.4 TESTING
39
3.4.1 MATERIAL CHARACTERIZATION
39
3.4.2 MECHANICAL PROPERTIES 39
CHAPTER 4: RESULTS AND DISCUSSION 42
4.1 FINITE ELEMENT MODELING 42
4.1.1 TEMPERATURE DISTRIBUTION SIMULATED FROM THE HEAT
TRANSFER MODEL
42
4.1.2 RESIDUAL THERMAL STRESSES OBTAINED FROM THE THERMO-
MECHANICAL MODEL
46
4.2 EXPERIMENTAL INVESTIGATION 52
v
4.2.1 EFFECT OF FRICTION STIR WELDING PARAMETERS ON THE PEAK
TEMPERATURE DURING THE WELDING PROCESS
52
4.2.2 COMPARISON BETWEEN THE SIMULATED AND THE MEASURED
TEMPERATURES
52
4.2.3 SURFACE MORPHOLOGY
55
4.2.4 MACROSTRUCTURE OF FRICTION STIR WELDED JOINTS AT DIFFERENT
OPERATION CONDITIONS
56
4.2.5 EFFECT OF FSW PARAMTERES ON THE MICROSTRUCTURE
EVOLUTIONS OF THE WELDED JOINTS
57
4.2.6 EFFECT OF FSW PARAMETERS ON THE MICROHARDNESS OF THE
WELDED JOINTS
70
4.2.7 EFFECT OF FSW PARAMETERS ON THE TENSILE STRENGTH VALUES
OF THE WELDED JOINTS
75
CONCLUSIONS
79
FUTURE WORK 80
REFERENCES 81
vi
List of Tables
Table 2.1 The effect of FSW parameters 6
Table 2.2 The relationship between the different contact conditions 23
Table 3.1 Temperature dependent thermal properties of AA5083 30
Table 3.2 Temperature dependent mechanical properties of AA5083 31
Table 3.3 The chemical composition of K720 36
Table 3.4 The chemical composition of AA5083-O 37
Table 3.5 The mechanical properties of AA5083-O 37
Table 3.6 FSW operation conditions 38
Table 4.1 The peak temperature variation due to variation of FSW parameters 55
Table 4.2 Average hardness values in the welding zone at various FSW conditions 75
Table 4.3 Tensile strength values at various FSW conditions 77
vii
List of Figures
Figure 2.1 FSW process set up 3
Figure 2.2 Schematic illustration of stages of FSW process 4
Figure 2.3 Schematic drawing of FSW tool 7
Figure 2.4 The commonly used tool pin profiles in FSW 7
Figure 2.5 The Whorl™ type probes 7
Figure 2.6 The Flared-Triflute™ type probes 8
Figure 2.7 Schematic drawing of tool tilting 9
Figure 2.8 The acting forces on the FSW tool 10
Figure 2.9 Schematic cross section showing zones of Al friction stir welded
joint
10
Figure2.10 Typical macrograph showing microstructure zones of AA2024 10
Figure2.11 Optical microstructures (SEM images) of FSW joint of 6013 T6 11
Figure 2.12 Optical microstructures of SZ at different rpms 12
Figure 2.13 Relationship between rotational speed and grain size of SZ of 2024-
T3
13
Figure 2.14 The effect of welding parameters on microstructures of DXZ of
AA2060 FSWed
13
Figure 2.15 Effect of welding and rotational speeds on the grain sizes in DXZ of
AA2060 FSWed
14
Figure 2.16 Hardness traces of AA5083-O and AA5083-H321 FSWed 15
Figure 2.17 Microhardness profiles and fracture locations of AA6061-T6 FSWed
at different welding conditions
16
Figure 2.18 Vickers Hardness profiles of FSWed joint cross section of AA5083
H-111
17
Figure 2.19 The effect of rotational speed on tensile properties of AA2024-T3
FSWed
18
Figure 2.20 Tensile strength variation of AA 5083-H111FSWed 19
Figure 2.21 The effect of rotational speed and tool pin profile on UTS of
AA5083-H111 FSWed
19
viii
Figure 2.22 Effect of welding speed on tensile properties of AA6061-T651
FSWed at 1600 rpm
20
Figure 2.23 Effect of rotational speed on tensile properties of AA6061-T651
FSWed at 0.2 mpm
20
Figure 2.24 Longitudinal residual stresses produced due to FSW of AA2024-
T351
21
Figure 2.25 Simulation of peak temperatures of AA6061-T6 at different
rotational and welding speeds
24
Figure 2.26 Numerical and experimental longitudinal residual stresses in cross
section of AA7075-T6 FSWed
25
Figure 2.27 The measured transverse residual stresses along and parallel to the
welding line of AA7075-T6 FSWed
25
Figure 3.1 Block diagram of the research plan 28
Figure 3.2 Block diagram of the finite element modeling 29
Figure 3.3 Part geometry 30
Figure 3.4 Boundary conditions subjected to the model 34
Figure 3.5 Thermal load subjected to the part 34
Figure 3.6 Part meshing 35
Figure 3.7 Schematic drawing of FSW tools 36
Figure 3.8 Machine set up 37
Figure 3.9 Schematic drawing of FSW process 38
Figure 3.10 Fluke IR thermal image camera 38
Figure 3.11 The measured temperature by using IR camera 38
Figure 3.12 OLYMPUS optical microscope 39
Figure 3.13 ZWICK/ROELL hardness testing machine 40
Figure 3.14 Schematic drawing of tension test sample cutting position 41
Figure 3.15 Schematic drawing of tension test specimen 41
Figure 3.16 Tension testing machine 41
Figure 4.1 Simulated temperature contour at different rotational speed values 42
Figure 4.2 Simulated temperature distribution plot perpendicular to the welding
line at different rotational speed values
43
Figure 4.3 Simulated temperature distribution plot along the welding line at
different rotational speed values
44
ix
Figure 4.4 Simulated temperature distribution plot along the model thickness at
different rotational speed values
45
Figure 4.5 Temperature history after 30 min. cooling for both rotational speeds 47
Figure 4.6 The longitudinal residual stresses contour at different rotational
speeds
48
Figure 4.7 The transverse residual stresses contour at different rotational speeds 48
Figure 4.8 The longitudinal residual stress plot at several paths perpendicular to
the welding line
49
Figure 4.9 The transverse residual stress plot at several paths along and parallel
to the welding line
50
Figure 4.10 The measured longitudinal residual stress obtained by Peel et al. 51
Figure 4.11 The measured transverse residual stresses along and parallel to the
welding line obtained by Buffa et al.
51
Figure 4.12 Variation of peak temperature due to variation of FSW parameters 53
Figure 4.13 Comparison between measured and simulated temperature
distributions at different rotational speed values
54
Figure 4.14 Surface morphologies of the welded joints by threaded tool pin
profile at different rotational and welding speeds
55
Figure 4.15 Surface morphologies of the welded joints by tapered tool pin profile
at different rotational and welding speeds
56
Figure 4.16 Macrostructure of the traverse cross section of the welded joints by
threaded pin at different rotational and welding speed values
57
Figure 4.17 Macrostructure of the traverse cross section of the welded joints by
tapered pin at different rotational and welding speed values
57
Figure 4.18 Microstructure of the welded joint by threaded pin at 400 rpm&50
mm/min
58
Figure 4.19 Microstructure of the welded joint by threaded pin at 400 rpm&100
mm/min
59
Figure 4.20 Microstructure of the welded joint by threaded pin at 400 rpm&160
mm/min
60
Figure 4.21 Microstructure of the welded joint by threaded pin at 630 rpm&50
mm/min
61
x
Figure 4.22 Microstructure of the welded joint by threaded pin at 630 rpm&100
mm/min
62
Figure 4.23 Microstructure of the welded joint by threaded pin at 630 rpm&160
mm/min
63
Figure 4.24 Microstructure of the welded joint by tapered pin at 400 rpm & 50
mm/min
64
Figure 4.25 Microstructure of the welded joint by tapered pin at 400 rpm &100
mm/min
65
Figure 4.26 Microstructure of the welded joint by tapered pin at 400 rpm&160
mm/min
66
Figure 4.27 Microstructure of the welded joint by tapered pin at 630 rpm&50
mm/min
67
Figure 4.28 Microstructure of the welded joint by tapered pin at 630 rpm&100
mm/min
68
Figure 4.29 Microstructure of the welded joint by tapered pin at 630 rpm&160
mm/min
69
Figure 4.30 Microhardness profile of the joints by the threaded pin profile at 400
rpm and different welding speeds
71
Figure 4.31 Microhardness profile of the joints by the threaded pin profile at 630
rpm and different welding speeds
72
Figure 4.32 Microhardness profile of the joints by the tapered pin profile at 400
rpm and different welding speeds
73
Figure 4.33 Microhardness profile of the joints by the tapered pin profile at 630
rpm and different welding speed
74
Figure 4.34 Effect of FSW parameters on the tensile strength values of the
welded joints
76
Figure 4.35 Fracture positions of the welded joints by threaded tool pin profile 77
Figure 4.36 Fracture positions of the welded joints by tapered tool pin profile 78
xi
Nomenclature
The contact shear stress
The friction coefficient
The contact pressure
The frictional heat generation
The slip rate
The contact state variable
The velocity of the tool
The velocity of the work piece
The rate of heat generation due to plastic energy dissipation
The factor of conversion of mechanical to thermal energy
The plastic strain rate
ρ The density
cp The specific heat
k The thermal conductivity
T The temperature
t The time
Q The heat flux
q The heat input
The angular velocity
n The rotational speed
F The axial force
R The shoulder radius
r The pin radius
ij The total strain
ijM
The strain contributed by the mechanical forces
ijT The stain from thermal loads
ijE The elastic strain
ij The Kronecker delta function
E The Young‟s modulus,
ν The Poisson‟s ratio,
α: The thermal expansion coefficient
The temperature difference of two different material points