The Effect Of Aging Heat Treatment On Hardness And Mechanical Properties Of Aluminium Alloy.
THE EFFECT OF AGING HEAT TREATMENT ON HARDNESS AND
MECHANICAL PROPERTIES OF ALUMINIUM ALLOY
NOOR MUHAMMAD JAMALLUDDIN BIN JUSOH
This report submitted in partial
Fulfilment of the requirements for the award of a Bachelor of
Mechanical Engineering (Structure & Materials)
Faculty of Mechanical Engineering
Universiti Teknikal Malaysia Melaka
v
ABSTRAK
Dalam kajian ini, mekanisme pengagihan semula Mg dan Si atom semasa proses
penuaan semula jadi telah dicadangkan. Hasil kajian ini untuk menentukan kesan penuaan
rawatan pada kekerasan dan sifat-sifat mekanik Aloi Aluminium 6061 selepas Proses
Rawatan Haba. Kesan penuaan semula jadi ditentukan berdasarkan perbandingan di antara
medium pelindapkejutan selepas Rawatan Haba Penyelesaian dan Rawatan Penuaan dalam
medium Relau dan penyejukan di Udara. Ujian bahan yang telah digunakan adalah
berdasarkan kekerasan, tegangan dan analisis mikrostruktur. Tujuan ujian kekerasan adalah
untuk mencari bacaan kekerasan untuk semua sampel yang digunakan untuk melihat kesan
keretakan yang berlaku selepas membuat merawat proses haba untuk aloi aluminium yang
6061. Daripada ujian tegangan, tujuan adalah untuk mengetahui tenaga tegangan yang
diserap untuk mematahkan sampel bahan dan kemudian membuat data perbandingan di
antara sebelum dan selepas rawatan haba. Akhir sekali, untuk analisa mikrostruktur ia adalah
penting untuk ditentukan kerana untuk melihat kesan proses penuaan dalam mikrostruktur
aloi aluminium selepas membuat proses rawatan haba. Daripada data dan hasil yang telah
ditentukan, ia menunjukkan hasil positif yang berdasarkan objektif dan skop projek ini.
vi
ABSTRACT
In this study, the mechanism of Mg and Si atom redistribution during the process of
natural aging has been proposed. The result of this study to determine the effect of aging
treatment on hardness and mechanical properties of Aluminum Alloy 6061 after Heat
Treatment Process. The effect of natural aging are determined based on comparison between
quenching medium after Solution Heat Treatment and Aging Treatment in medium of
Furnace and cooling in Air. The material testing that had been applied is based on hardness,
tensile and microstructure analysis. The purpose of the hardness testing are to find out the
hardness reading for all samples that used to look fracture effect that occur after make a heat
treating process to the aluminum alloy 6061. From the tensile test, the purposes are to know
tensile energy that absorbed to fracture the samples of the material and then make a
comparison data between after and before heat treatment. Lastly, for microstructure analysis
it is important to determine because to look the effect of aging process in the microstructure
of aluminum alloy after make heat treatment process. From the data and result that already
determined, it shown the positive result based on the objectives and scope of this project.
TABLE OF CONTENT
CHAPTER
CHAPTER 1
TOPIC
PAGES
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRAK
v
ABSTRACT
vi
TABLE OF CONTENT
ix
LIST OF FIGURES
xv
LIST OF TABLES
xix
LIST OF SYMBOLS
xxi
LIST OF APPENDIXS
xxii
INTRODUCTION
1.1 Background
1
1.2 Problem Statement
2
1.3 Objectives
3
1.4 Scopes
3
1.5 Overview of the project
3
CHAPTER 2
LITERATURE REVIEW
2.1 Aluminum
4
2.2 Aluminum Alloy
6
2.3 Application of Aluminum Alloy
2.3.1 Transport
7
2.3.2 Aeronautics
7
2.3.3 Construction
8
2.3.4 Architectural Sheet
9
2.3.5 Electrical and Thermal Applications
9
2.3.6 Packaging
10
2.3.7 Domestic
10
2.4 6061 Aluminum Alloy
CHAPTER 3
11
2.4.1 Aluminum Alloy Series System
11
2.4.2 Composition
12
2.4.3 Location in Periodic Table
12
2.4.4 Phase Diagram
13
2.4.5 Application
14
2.4.5.1
Dynamo Lighting System
14
2.4.5.2
Modular Crossover Platform
15
2.4.5.3
Bicycle Frame
15
2.4.5.4
Hemi Spark Plug Tubes
16
METHODOLOGY
3.1 Flow Chart
17
3.2 Laboratory Process
18
3.3 Specimen
19
3.3.1 Shape of Specimen
19
3.3.2 Specimen Drawing
19
3.3.3 Specimen Dimensions
20
3.3.4 Quantity of Specimen
20
3.4 Process
3.4.1 Sample Preparation
21
3.4.2 CNC Lathe Machine
22
3.4.3 Heat Treatment Process
CHAPTER 4
3.4.3.1 Purpose
24
3.4.3.2 Solution Heat Treatment
24
3.4.3.3 Quenching
26
3.4.4 Hardness Test
27
3.4.5 Tensile Test
28
3.4.6 Microstructure Observation
29
3.4.6.1 Microstructural
30
3.4.6.2 Diagram
30
3.4.6.3 Microscopic Examination
30
RESULTS
4.1 Hardness Test
38
4.2 Tensile Test
40
4.3 Stress Strain
4.3.1
Stress Strain Specimen 1
42
4.3.2
Stress Strain Specimen 2
43
4.3.3
Stress Strain Specimen 3
44
4.3.4
Stress Strain Specimen 4
45
4.3.5
Stress Strain Specimen 5
46
4.3.6
Stress Strain Specimen 6
47
4.3.7
Stress Strain Specimen 7
48
4.3.8
Stress Strain Specimen 8
49
4.3.9
Stress Strain Specimen 9
50
4.3.1.0 Stress Strain Specimen 10
51
4.3.1.1 Stress Strain Specimen 11
52
4.3.1.2 Stress Strain Specimen 12
53
4.3.1.3 Stress Strain Specimen 13
54
4.3.1.4 Stress Strain Specimen 14
55
4.3.1.5 Stress Strain Specimen 15
56
4.3.1.6 Stress Strain Specimen 16
57
4.3.1.7 Stress Strain Specimen 17
58
4.3.1.8 Stress Strain Specimen 18
59
4.3.1.9 Stress Strain Specimen 19
60
4.3.2.0 Stress Strain Specimen 20
61
4.5 Microstructure Using Optical Microscope
CHAPTER 5
62
DISCUSSION
5.1
Effect of Aging Treatment on Aluminum Alloy
63
5.2
Effect of Aging Treatment in Quenching
64
5.3
Effect of Aging Treatment on Hardness
66
5.4
Effect of Aging Treatment on Mechanical
5.4.1 Ductility
69
5.4.2
Stress and Strain
69
5.4.3
Microstructure
72
CHAPTER 6
CONCLUSION
6.1
Recommendation
75
6.2
Conclusion
78
6.3
Appendix
79-91
LIST OF FIGURES
PAGES
NO
TOPIC
1.2
Cup and Cone Aluminum Alloy Fracture
2
2.1
Element of Aluminum
5
2.2
Production
6
2.4
Sample Product
11
2.4.4 (a)
Al-Mg Phase Diagram
13
2.4.4 (b)
Al-Si Phase Diagram
14
3.1
Flow Chart
17
3.3.1
Specimen
19
3.3.2
Drawing
19
3.3.3
Specimen Dimension
20
3.4.1 (a)
Milling Machine
21
3.4.1 (b)
Cutting Material
22
3.4.2 (a)
CNC Lathe Machine
22
3.4.2 (b)
Shape The Specimen
23
3.4.3
Furnace
24
3.4.3.3 (a)
Cooling in Air
26
3.4.3.3 (b)
Cooling in Furnace
26
3.4.4
Rockwell Hardness
27
3.4.5
INSTRON Equipment
28
3.4.6
Microscope
29
3.4.6.2
Change of Microstructure
30
3.4.6.3.1
Cutting
31
3.4.6.3.2
Mounting Machine
31
3.4.6.3.3
Smooth Face
32
3.4.6.3.4
Centre The Specimen
33
3.4.6.3.5
Pour The Resin
33
3.4.6.3.6
Pressure Setting
34
3.4.6.3.7
Grinding Machine
35
3.4.6.3.8
Ultrasonic Bath
35
3.4.6.3.9
Keller’s Reagent
36
4.3.1
Stress Strain Graph for Specimen 1
42
4.3.2
Stress Strain Graph for Specimen 2
43
4.3.3
Stress Strain Graph for Specimen 3
44
4.3.4
Stress Strain Graph for Specimen 4
45
4.3.5
Stress Strain Graph for Specimen 5
46
4.3.6
Stress Strain Graph for Specimen 6
47
4.3.7
Stress Strain Graph for Specimen 7
48
4.3.8
Stress Strain Graph for Specimen 8
49
4.3.9
Stress Strain Graph for Specimen 9
50
4.3.1.0
Stress Strain Graph for Specimen 10
51
4.3.1.1
Stress Strain Graph for Specimen 11
52
4.3.1.2
Stress Strain Graph for Specimen 12
53
4.3.1.3
Stress Strain Graph for Specimen 13
54
4.3.1.4
Stress Strain Graph for Specimen 14
55
4.3.1.5
Stress Strain Graph for Specimen 15
56
4.3.1.6
Stress Strain Graph for Specimen 16
57
4.3.1.7
Stress Strain Graph for Specimen 17
58
4.3.1.8
Stress Strain Graph for Specimen 18
59
4.3.1.9
Stress Strain Graph for Specimen 19
60
4.3.2.0
Stress Strain Graph for Specimen 20
61
4.4 (a) (b)
For Cooling in Furnace
62
4.4 (c ) (d)
For Cooling in Air
62
5.4.1
Moderately Ductile Failure
69
5.4.2
Principal of Stress Strain
70
LIST OF TABLES
NO
TOPIC
2.4.1
The Major Alloying Element Grouped of Aluminum
PAGES
12
Alloy
2.4.2
Typical Composition of Aluminum Alloy 6061
12
2.4.3
Major Element of 6061 in Periodic Table
13
3.2
Laboratory Process
18
3.3.4
Quantity of Specimen
20
3.4.3
Specimen for Heat Treatment Process
23
3.4.4
Typical Scale Applications
28
4.1
Hardness Value for All Specimen
39
4.2 (a)
Tensile Test for Cooling in Furnace
41
4.2 (b)
Tensile Test for Cooling in Air
41
4.3.1
Data Stress Strain for Specimen 1
42
4.3.2
Data Stress Strain for Specimen 2
43
4.3.3
Data Stress Strain for Specimen 3
44
4.3.4
Data Stress Strain for Specimen 4
45
4.3.5
Data Stress Strain for Specimen 5
46
4.3.6
Data Stress Strain for Specimen 6
47
4.3.7
Data Stress Strain for Specimen 7
48
4.3.8
Data Stress Strain for Specimen 8
49
4.3.9
Data Stress Strain for Specimen 9
50
4.3.1.0
Data Stress Strain for Specimen 10
51
4.3.1.1
Data Stress Strain for Specimen 11
52
4.3.1.2
Data Stress Strain for Specimen 12
53
4.3.1.3
Data Stress Strain for Specimen 13
54
4.3.1.4
Data Stress Strain for Specimen 14
55
4.3.1.5
Data Stress Strain for Specimen 15
56
4.3.1.6
Data Stress Strain for Specimen 16
57
4.3.1.7
Data Stress Strain for Specimen 17
58
4.3.1.8
Data Stress Strain for Specimen 18
59
4.3.1.9
Data Stress Strain for Specimen 19
60
4.3.2.0
Data Stress Strain for Specimen 20
61
LIST OF SYMBOLS
MPa
=
Unit for Tensile Strength
0°C
=
Celsius
CNC
=
A lathe that is controlled by a computer running
Programming driven by numerical data
mm
=
milimetre
%
=
Percentage
Al
=
Aluminum
T
=
Temperature
N
=
Newton
S
=
Second
LIST OF APPENDIXS
NO
TITLE
PAGES
1
Gantt Chart PSM 1
79
2
Gantt Chart PSM 2
79
3
Poster PSM 1
80
4
Poster PSM 2
81
5
Graph Load Versus Extension
82-91
1
CHAPTER 1
INTRODUCTION
1.1
BACKGROUND
In recent years, aluminium alloys have attracted attention of many researcher,
engineers and designers as promising structural materials for automotive industry or
aerospace applications. Aluminium alloys are alloys in which aluminium is the predominant
metal. Aluminium alloys are widely used in engineering structures and components where
light weight or corrosion resistance is required. There are many type of aluminium alloy
series in it alloy systems which the each series has their own mechanical and physical
properties depends on the composition in that alloys. (P.J Gregson and S.J Harris, 2002).
Aluminium alloys can be divided into two categories: non-heat treatable and heat treatable.
Extensive studies have been done on the 6xxx aluminium alloys because of their benefits
compared to the other type of aluminium. It has good mechanical properties and exhibits
good weldability. The 6061 aluminium alloys has been used in the automotive industry for
the fabrication of several types of automobile parts such as wheel spacers, panels and even in
the vehicle structure. Several of aluminium alloy mechanical properties can be change by
doing a specific heat treatment. Generally aluminium alloys can be heat treated to increase
their mechanical properties especially their strength, hardness and also improves their fatigue
resistance.
2
1.2
PROBLEM STATEMENT
A lot of researches have been done by the researcher all around the world on this
aluminium alloy especially for industrial use. They have studied about the strength,
formability, weldability and many more. The effect of variation aging time on machinability
of 6061 aluminium alloy which has been heat treated to specific temperature has been
investigate in this project. The purpose is to see whether the 6061 aluminium alloy
mechanical properties is being affected or not by the variation aging time at specific
temperature. Then the result is being compared to the result from the previous experiment
that has been done by other researchers. Aluminum is one of the most widely used metals and
also one of the most frequently found compounds in the earth’s crust. Disadvantages of
Aluminum is not particularly strong the strongest varieties are around 517 MPa tensile
strength, is not very hard and it’s easy to scratch. As a result, this project is to try to prove
that the hardness after the Heat Treatment larger than before the Heat Treatment. In addition,
it also perform microstructure which it described on it behaviours. These could be divided to
Mechanical Properties as Young’s Modulus, ultimate Tensile Strength, Tensile Strength and
Yield Strength. Besides, the strength of material had a difference before and after the Heat
Treatment. Nowadays, better and more consistent alloys and composite materials are all
contributing to new structural designs [1]. Among the light metals, although aluminium itself
is soft and low in strength it can be made stronger by giving proper combination of suitable
alloy [2].
Figure 1.2: Cup and Cone Aluminium Fracture
(Source: H.W. Hayden, W.G Moffatt and J. Wulf , (1945) )
3
1.3
OBJECTIVES
The objectives of the project that need to be achieved are:
1. To study the effect of aging treatment on hardness of aluminium alloy after Heat
Treatment in comparison cooling in air and cooling in furnace.
2. To study the effect of aging treatment to mechanical properties of aluminium alloy
after Heat Treatment Process in comparison cooling in furnace and cooling in air.
1.4
SCOPES
The focus area will be done based on the following aspect:
1.
6061 aluminium alloy sample preparation.
2.
Aging Treatment temperature at 150°C, 200°C and 250°C.
3.
Artificial aging of sample at 1 hour, 3 hours and 5 hours.
4.
Specimen preparation by using the CNC Lathe machine.
5. ` Microstructure observation by using optical microscope.
Tensile Test by using INSTRON Equipment
7.
Hardness test by using hardness test machine.
1.5
6.
OVERVIEW OF THE REPORT
This project has been sort into six chapters. The introduction of the project has been
show in chapter 1. In chapter 2, the literature review has been explained. Methodology is
being told in chapter 3 while in chapter 4 are result, chapter 5 are discussion and lastly
chapter 6 about conclusion.
4
CHAPTER 2
LITERATURE REVIEW
Literature review is a body of text that aims to review the critical points of current
knowledge and or methodological approaches on a particular topic. In this chapter, the
literature that will give information about this project and what happen during this
experiment is being discussed. This project is intended to provide a lot of information about
extensive background of Heat Treatment process with detail explanations as a reference for
this project. The chapter begins with general overview of Heat Treatment and it types, details
about Aluminum and few types of Testing.
2.1
ALUMINIUM
Aluminium, symbol Al, the most abundant metallic element in the Earth's crust. The
atomic number of aluminium is 13; the element is in group 3 of the periodic table. Pure
aluminium has a face centred cubic crystal structure.
Aluminium is a very light metal with a specific weight of 2.7 kg dm−3, about a third
that of steel. For example, the use of aluminium in vehicles reduces dead-weight and energy
consumption while increasing load capacity. Its strength can be adapted to the application
required by modifying the composition of its alloys and by various thermal and mechanical
treatments.
Aluminium naturally generates a protective oxide coating and is highly corrosion
resistant. Different types of surface treatment such as anodising, painting or lacquering can
5
further improve this property. It is particularly useful for applications where protection and
conservation are required.
Aluminium is an excellent heat and electricity conductor and in relation to its weight
is almost twice as good a conductor as copper. This has made aluminium the most commonly
used material in major power transmission lines.
Aluminium is a good reflector of visible light as well as heat, and that together with
its low weight makes it an ideal material for reflectors in, for example, light fittings or rescue
blankets.
Aluminium is ductile and has a low melting point and density. In a molten condition it
can be processed in a number of ways. Its ductility allows products of aluminium to be
basically formed close to the end of the products design.
Aluminium foil, even when it is rolled to only 0.007 mm thickness, is still completely
impermeable and let’s neither light aroma nor taste substances out. Moreover, the metal itself
is non-toxic and releases no aroma or taste substances which make it ideal for packaging
sensitive products such as food or pharmaceuticals.
Aluminium is 100% recyclable with no downgrading of its qualities. The re-melting
of aluminium requires little energy: only about 5% of the energy required to produce the
primary metal initially is needed in the recycling process
Figure 2.1: Element of Aluminium
(Source: Greg Robson)
6
2.2
ALUMINIUM ALLOY
Aluminium alloys are alloys in which aluminium is the predominant metal.
Typical alloying elements are copper, zinc, manganese, silicon, and magnesium. About 85%
of aluminium is used for wrought products, for example rolled plate, foils and extrusions.
Cast aluminium alloys yield cost effective products due to the low melting point, although
they generally have lower tensile strengths than wrought alloys. The most important cast
aluminium alloy system is Al-Si, where the high levels of silicon (4-13%) contribute to give
good casting characteristics. Aluminium alloys are widely used in engineering structures and
components where light weight or corrosion resistance is required.
Figure 2.2: Production
MECHANICAL PROPERTIES OF ALUMINIUM ALLOY
NOOR MUHAMMAD JAMALLUDDIN BIN JUSOH
This report submitted in partial
Fulfilment of the requirements for the award of a Bachelor of
Mechanical Engineering (Structure & Materials)
Faculty of Mechanical Engineering
Universiti Teknikal Malaysia Melaka
v
ABSTRAK
Dalam kajian ini, mekanisme pengagihan semula Mg dan Si atom semasa proses
penuaan semula jadi telah dicadangkan. Hasil kajian ini untuk menentukan kesan penuaan
rawatan pada kekerasan dan sifat-sifat mekanik Aloi Aluminium 6061 selepas Proses
Rawatan Haba. Kesan penuaan semula jadi ditentukan berdasarkan perbandingan di antara
medium pelindapkejutan selepas Rawatan Haba Penyelesaian dan Rawatan Penuaan dalam
medium Relau dan penyejukan di Udara. Ujian bahan yang telah digunakan adalah
berdasarkan kekerasan, tegangan dan analisis mikrostruktur. Tujuan ujian kekerasan adalah
untuk mencari bacaan kekerasan untuk semua sampel yang digunakan untuk melihat kesan
keretakan yang berlaku selepas membuat merawat proses haba untuk aloi aluminium yang
6061. Daripada ujian tegangan, tujuan adalah untuk mengetahui tenaga tegangan yang
diserap untuk mematahkan sampel bahan dan kemudian membuat data perbandingan di
antara sebelum dan selepas rawatan haba. Akhir sekali, untuk analisa mikrostruktur ia adalah
penting untuk ditentukan kerana untuk melihat kesan proses penuaan dalam mikrostruktur
aloi aluminium selepas membuat proses rawatan haba. Daripada data dan hasil yang telah
ditentukan, ia menunjukkan hasil positif yang berdasarkan objektif dan skop projek ini.
vi
ABSTRACT
In this study, the mechanism of Mg and Si atom redistribution during the process of
natural aging has been proposed. The result of this study to determine the effect of aging
treatment on hardness and mechanical properties of Aluminum Alloy 6061 after Heat
Treatment Process. The effect of natural aging are determined based on comparison between
quenching medium after Solution Heat Treatment and Aging Treatment in medium of
Furnace and cooling in Air. The material testing that had been applied is based on hardness,
tensile and microstructure analysis. The purpose of the hardness testing are to find out the
hardness reading for all samples that used to look fracture effect that occur after make a heat
treating process to the aluminum alloy 6061. From the tensile test, the purposes are to know
tensile energy that absorbed to fracture the samples of the material and then make a
comparison data between after and before heat treatment. Lastly, for microstructure analysis
it is important to determine because to look the effect of aging process in the microstructure
of aluminum alloy after make heat treatment process. From the data and result that already
determined, it shown the positive result based on the objectives and scope of this project.
TABLE OF CONTENT
CHAPTER
CHAPTER 1
TOPIC
PAGES
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRAK
v
ABSTRACT
vi
TABLE OF CONTENT
ix
LIST OF FIGURES
xv
LIST OF TABLES
xix
LIST OF SYMBOLS
xxi
LIST OF APPENDIXS
xxii
INTRODUCTION
1.1 Background
1
1.2 Problem Statement
2
1.3 Objectives
3
1.4 Scopes
3
1.5 Overview of the project
3
CHAPTER 2
LITERATURE REVIEW
2.1 Aluminum
4
2.2 Aluminum Alloy
6
2.3 Application of Aluminum Alloy
2.3.1 Transport
7
2.3.2 Aeronautics
7
2.3.3 Construction
8
2.3.4 Architectural Sheet
9
2.3.5 Electrical and Thermal Applications
9
2.3.6 Packaging
10
2.3.7 Domestic
10
2.4 6061 Aluminum Alloy
CHAPTER 3
11
2.4.1 Aluminum Alloy Series System
11
2.4.2 Composition
12
2.4.3 Location in Periodic Table
12
2.4.4 Phase Diagram
13
2.4.5 Application
14
2.4.5.1
Dynamo Lighting System
14
2.4.5.2
Modular Crossover Platform
15
2.4.5.3
Bicycle Frame
15
2.4.5.4
Hemi Spark Plug Tubes
16
METHODOLOGY
3.1 Flow Chart
17
3.2 Laboratory Process
18
3.3 Specimen
19
3.3.1 Shape of Specimen
19
3.3.2 Specimen Drawing
19
3.3.3 Specimen Dimensions
20
3.3.4 Quantity of Specimen
20
3.4 Process
3.4.1 Sample Preparation
21
3.4.2 CNC Lathe Machine
22
3.4.3 Heat Treatment Process
CHAPTER 4
3.4.3.1 Purpose
24
3.4.3.2 Solution Heat Treatment
24
3.4.3.3 Quenching
26
3.4.4 Hardness Test
27
3.4.5 Tensile Test
28
3.4.6 Microstructure Observation
29
3.4.6.1 Microstructural
30
3.4.6.2 Diagram
30
3.4.6.3 Microscopic Examination
30
RESULTS
4.1 Hardness Test
38
4.2 Tensile Test
40
4.3 Stress Strain
4.3.1
Stress Strain Specimen 1
42
4.3.2
Stress Strain Specimen 2
43
4.3.3
Stress Strain Specimen 3
44
4.3.4
Stress Strain Specimen 4
45
4.3.5
Stress Strain Specimen 5
46
4.3.6
Stress Strain Specimen 6
47
4.3.7
Stress Strain Specimen 7
48
4.3.8
Stress Strain Specimen 8
49
4.3.9
Stress Strain Specimen 9
50
4.3.1.0 Stress Strain Specimen 10
51
4.3.1.1 Stress Strain Specimen 11
52
4.3.1.2 Stress Strain Specimen 12
53
4.3.1.3 Stress Strain Specimen 13
54
4.3.1.4 Stress Strain Specimen 14
55
4.3.1.5 Stress Strain Specimen 15
56
4.3.1.6 Stress Strain Specimen 16
57
4.3.1.7 Stress Strain Specimen 17
58
4.3.1.8 Stress Strain Specimen 18
59
4.3.1.9 Stress Strain Specimen 19
60
4.3.2.0 Stress Strain Specimen 20
61
4.5 Microstructure Using Optical Microscope
CHAPTER 5
62
DISCUSSION
5.1
Effect of Aging Treatment on Aluminum Alloy
63
5.2
Effect of Aging Treatment in Quenching
64
5.3
Effect of Aging Treatment on Hardness
66
5.4
Effect of Aging Treatment on Mechanical
5.4.1 Ductility
69
5.4.2
Stress and Strain
69
5.4.3
Microstructure
72
CHAPTER 6
CONCLUSION
6.1
Recommendation
75
6.2
Conclusion
78
6.3
Appendix
79-91
LIST OF FIGURES
PAGES
NO
TOPIC
1.2
Cup and Cone Aluminum Alloy Fracture
2
2.1
Element of Aluminum
5
2.2
Production
6
2.4
Sample Product
11
2.4.4 (a)
Al-Mg Phase Diagram
13
2.4.4 (b)
Al-Si Phase Diagram
14
3.1
Flow Chart
17
3.3.1
Specimen
19
3.3.2
Drawing
19
3.3.3
Specimen Dimension
20
3.4.1 (a)
Milling Machine
21
3.4.1 (b)
Cutting Material
22
3.4.2 (a)
CNC Lathe Machine
22
3.4.2 (b)
Shape The Specimen
23
3.4.3
Furnace
24
3.4.3.3 (a)
Cooling in Air
26
3.4.3.3 (b)
Cooling in Furnace
26
3.4.4
Rockwell Hardness
27
3.4.5
INSTRON Equipment
28
3.4.6
Microscope
29
3.4.6.2
Change of Microstructure
30
3.4.6.3.1
Cutting
31
3.4.6.3.2
Mounting Machine
31
3.4.6.3.3
Smooth Face
32
3.4.6.3.4
Centre The Specimen
33
3.4.6.3.5
Pour The Resin
33
3.4.6.3.6
Pressure Setting
34
3.4.6.3.7
Grinding Machine
35
3.4.6.3.8
Ultrasonic Bath
35
3.4.6.3.9
Keller’s Reagent
36
4.3.1
Stress Strain Graph for Specimen 1
42
4.3.2
Stress Strain Graph for Specimen 2
43
4.3.3
Stress Strain Graph for Specimen 3
44
4.3.4
Stress Strain Graph for Specimen 4
45
4.3.5
Stress Strain Graph for Specimen 5
46
4.3.6
Stress Strain Graph for Specimen 6
47
4.3.7
Stress Strain Graph for Specimen 7
48
4.3.8
Stress Strain Graph for Specimen 8
49
4.3.9
Stress Strain Graph for Specimen 9
50
4.3.1.0
Stress Strain Graph for Specimen 10
51
4.3.1.1
Stress Strain Graph for Specimen 11
52
4.3.1.2
Stress Strain Graph for Specimen 12
53
4.3.1.3
Stress Strain Graph for Specimen 13
54
4.3.1.4
Stress Strain Graph for Specimen 14
55
4.3.1.5
Stress Strain Graph for Specimen 15
56
4.3.1.6
Stress Strain Graph for Specimen 16
57
4.3.1.7
Stress Strain Graph for Specimen 17
58
4.3.1.8
Stress Strain Graph for Specimen 18
59
4.3.1.9
Stress Strain Graph for Specimen 19
60
4.3.2.0
Stress Strain Graph for Specimen 20
61
4.4 (a) (b)
For Cooling in Furnace
62
4.4 (c ) (d)
For Cooling in Air
62
5.4.1
Moderately Ductile Failure
69
5.4.2
Principal of Stress Strain
70
LIST OF TABLES
NO
TOPIC
2.4.1
The Major Alloying Element Grouped of Aluminum
PAGES
12
Alloy
2.4.2
Typical Composition of Aluminum Alloy 6061
12
2.4.3
Major Element of 6061 in Periodic Table
13
3.2
Laboratory Process
18
3.3.4
Quantity of Specimen
20
3.4.3
Specimen for Heat Treatment Process
23
3.4.4
Typical Scale Applications
28
4.1
Hardness Value for All Specimen
39
4.2 (a)
Tensile Test for Cooling in Furnace
41
4.2 (b)
Tensile Test for Cooling in Air
41
4.3.1
Data Stress Strain for Specimen 1
42
4.3.2
Data Stress Strain for Specimen 2
43
4.3.3
Data Stress Strain for Specimen 3
44
4.3.4
Data Stress Strain for Specimen 4
45
4.3.5
Data Stress Strain for Specimen 5
46
4.3.6
Data Stress Strain for Specimen 6
47
4.3.7
Data Stress Strain for Specimen 7
48
4.3.8
Data Stress Strain for Specimen 8
49
4.3.9
Data Stress Strain for Specimen 9
50
4.3.1.0
Data Stress Strain for Specimen 10
51
4.3.1.1
Data Stress Strain for Specimen 11
52
4.3.1.2
Data Stress Strain for Specimen 12
53
4.3.1.3
Data Stress Strain for Specimen 13
54
4.3.1.4
Data Stress Strain for Specimen 14
55
4.3.1.5
Data Stress Strain for Specimen 15
56
4.3.1.6
Data Stress Strain for Specimen 16
57
4.3.1.7
Data Stress Strain for Specimen 17
58
4.3.1.8
Data Stress Strain for Specimen 18
59
4.3.1.9
Data Stress Strain for Specimen 19
60
4.3.2.0
Data Stress Strain for Specimen 20
61
LIST OF SYMBOLS
MPa
=
Unit for Tensile Strength
0°C
=
Celsius
CNC
=
A lathe that is controlled by a computer running
Programming driven by numerical data
mm
=
milimetre
%
=
Percentage
Al
=
Aluminum
T
=
Temperature
N
=
Newton
S
=
Second
LIST OF APPENDIXS
NO
TITLE
PAGES
1
Gantt Chart PSM 1
79
2
Gantt Chart PSM 2
79
3
Poster PSM 1
80
4
Poster PSM 2
81
5
Graph Load Versus Extension
82-91
1
CHAPTER 1
INTRODUCTION
1.1
BACKGROUND
In recent years, aluminium alloys have attracted attention of many researcher,
engineers and designers as promising structural materials for automotive industry or
aerospace applications. Aluminium alloys are alloys in which aluminium is the predominant
metal. Aluminium alloys are widely used in engineering structures and components where
light weight or corrosion resistance is required. There are many type of aluminium alloy
series in it alloy systems which the each series has their own mechanical and physical
properties depends on the composition in that alloys. (P.J Gregson and S.J Harris, 2002).
Aluminium alloys can be divided into two categories: non-heat treatable and heat treatable.
Extensive studies have been done on the 6xxx aluminium alloys because of their benefits
compared to the other type of aluminium. It has good mechanical properties and exhibits
good weldability. The 6061 aluminium alloys has been used in the automotive industry for
the fabrication of several types of automobile parts such as wheel spacers, panels and even in
the vehicle structure. Several of aluminium alloy mechanical properties can be change by
doing a specific heat treatment. Generally aluminium alloys can be heat treated to increase
their mechanical properties especially their strength, hardness and also improves their fatigue
resistance.
2
1.2
PROBLEM STATEMENT
A lot of researches have been done by the researcher all around the world on this
aluminium alloy especially for industrial use. They have studied about the strength,
formability, weldability and many more. The effect of variation aging time on machinability
of 6061 aluminium alloy which has been heat treated to specific temperature has been
investigate in this project. The purpose is to see whether the 6061 aluminium alloy
mechanical properties is being affected or not by the variation aging time at specific
temperature. Then the result is being compared to the result from the previous experiment
that has been done by other researchers. Aluminum is one of the most widely used metals and
also one of the most frequently found compounds in the earth’s crust. Disadvantages of
Aluminum is not particularly strong the strongest varieties are around 517 MPa tensile
strength, is not very hard and it’s easy to scratch. As a result, this project is to try to prove
that the hardness after the Heat Treatment larger than before the Heat Treatment. In addition,
it also perform microstructure which it described on it behaviours. These could be divided to
Mechanical Properties as Young’s Modulus, ultimate Tensile Strength, Tensile Strength and
Yield Strength. Besides, the strength of material had a difference before and after the Heat
Treatment. Nowadays, better and more consistent alloys and composite materials are all
contributing to new structural designs [1]. Among the light metals, although aluminium itself
is soft and low in strength it can be made stronger by giving proper combination of suitable
alloy [2].
Figure 1.2: Cup and Cone Aluminium Fracture
(Source: H.W. Hayden, W.G Moffatt and J. Wulf , (1945) )
3
1.3
OBJECTIVES
The objectives of the project that need to be achieved are:
1. To study the effect of aging treatment on hardness of aluminium alloy after Heat
Treatment in comparison cooling in air and cooling in furnace.
2. To study the effect of aging treatment to mechanical properties of aluminium alloy
after Heat Treatment Process in comparison cooling in furnace and cooling in air.
1.4
SCOPES
The focus area will be done based on the following aspect:
1.
6061 aluminium alloy sample preparation.
2.
Aging Treatment temperature at 150°C, 200°C and 250°C.
3.
Artificial aging of sample at 1 hour, 3 hours and 5 hours.
4.
Specimen preparation by using the CNC Lathe machine.
5. ` Microstructure observation by using optical microscope.
Tensile Test by using INSTRON Equipment
7.
Hardness test by using hardness test machine.
1.5
6.
OVERVIEW OF THE REPORT
This project has been sort into six chapters. The introduction of the project has been
show in chapter 1. In chapter 2, the literature review has been explained. Methodology is
being told in chapter 3 while in chapter 4 are result, chapter 5 are discussion and lastly
chapter 6 about conclusion.
4
CHAPTER 2
LITERATURE REVIEW
Literature review is a body of text that aims to review the critical points of current
knowledge and or methodological approaches on a particular topic. In this chapter, the
literature that will give information about this project and what happen during this
experiment is being discussed. This project is intended to provide a lot of information about
extensive background of Heat Treatment process with detail explanations as a reference for
this project. The chapter begins with general overview of Heat Treatment and it types, details
about Aluminum and few types of Testing.
2.1
ALUMINIUM
Aluminium, symbol Al, the most abundant metallic element in the Earth's crust. The
atomic number of aluminium is 13; the element is in group 3 of the periodic table. Pure
aluminium has a face centred cubic crystal structure.
Aluminium is a very light metal with a specific weight of 2.7 kg dm−3, about a third
that of steel. For example, the use of aluminium in vehicles reduces dead-weight and energy
consumption while increasing load capacity. Its strength can be adapted to the application
required by modifying the composition of its alloys and by various thermal and mechanical
treatments.
Aluminium naturally generates a protective oxide coating and is highly corrosion
resistant. Different types of surface treatment such as anodising, painting or lacquering can
5
further improve this property. It is particularly useful for applications where protection and
conservation are required.
Aluminium is an excellent heat and electricity conductor and in relation to its weight
is almost twice as good a conductor as copper. This has made aluminium the most commonly
used material in major power transmission lines.
Aluminium is a good reflector of visible light as well as heat, and that together with
its low weight makes it an ideal material for reflectors in, for example, light fittings or rescue
blankets.
Aluminium is ductile and has a low melting point and density. In a molten condition it
can be processed in a number of ways. Its ductility allows products of aluminium to be
basically formed close to the end of the products design.
Aluminium foil, even when it is rolled to only 0.007 mm thickness, is still completely
impermeable and let’s neither light aroma nor taste substances out. Moreover, the metal itself
is non-toxic and releases no aroma or taste substances which make it ideal for packaging
sensitive products such as food or pharmaceuticals.
Aluminium is 100% recyclable with no downgrading of its qualities. The re-melting
of aluminium requires little energy: only about 5% of the energy required to produce the
primary metal initially is needed in the recycling process
Figure 2.1: Element of Aluminium
(Source: Greg Robson)
6
2.2
ALUMINIUM ALLOY
Aluminium alloys are alloys in which aluminium is the predominant metal.
Typical alloying elements are copper, zinc, manganese, silicon, and magnesium. About 85%
of aluminium is used for wrought products, for example rolled plate, foils and extrusions.
Cast aluminium alloys yield cost effective products due to the low melting point, although
they generally have lower tensile strengths than wrought alloys. The most important cast
aluminium alloy system is Al-Si, where the high levels of silicon (4-13%) contribute to give
good casting characteristics. Aluminium alloys are widely used in engineering structures and
components where light weight or corrosion resistance is required.
Figure 2.2: Production