The Al 7075 alloy is a very useful material because of its mechanical properties i.e. low density, high strength, moderate ductility and toughness. Due to these properties, this alloy is mainly used for highly stressed structural parts. This material has a wide range of application such as aircraft fittings, gears and shafts, fuse parts, meter shafts and gear, missile parts , regulating valve parts, worm gears, keys and various other parts of commercial aircrafts and aerospace vehicles.

1. A PROJECT ON
STUDY THE MECHANICAL BEHAVIOUR OF Al 7075
ALLOY BASED COMPOSITES BY COMPRESSION
METHOD
Project report submitted in partial fulfillment of the Requirements for the Award of the
Degree of B.Tech
In
Metallurgical Engineering
BY
JEETENDRAMAHARANA ,14MET039
Under the Esteemed Guidance of
Dr. R.GOVINDA RAO
Associate Professor
Department of Metallurgical Engineering
Gandhi Institute of Engineering and Technology
(Autonomous)
(Affiliated to BPUT, Rourkela)
Approved by AICTE- Accredited by NBA
Gunupur-765022
2018

2. Declaration
I declare that this written submission represents my ideas in my own words and where others'
ideas or words have been included, I have adequately cited and referenced the original
sources. I also declare that I have adhered to all principles of academic honesty and integrity
and have not misrepresented or fabricated or falsified any idea/data/fact/ source in my
submission. I understand that any violation of the above will be cause for disciplinary action
by the Institute and can also evoke penal action from the sources which have thus not been
properly cited or from whom proper permission has not been taken when needed.
J
EETANDRA MAHARANA 14MET039
Date:

3. Approval Sheet
This project report entitled “A PROJECT ON STUDY THE MECHANICAL
BEHAVIOUR OF Al 7075 ALLOY BASED COMPOSITE BY COMPRESSION
METHOD” by E.TIRUPATI, JEETENDRA MAHARANA, SONA KAMALESH PARIDA,
CHIRANJIBEE KUMAR MAHANTA is approved for the degree of Metallurgical
Engineering.
Examiners
________________________
________________________
________________________
Supervisor (s)
________________________
________________________
________________________
HOD, Metallurgical Engg.
________________________
Date :____________
Place:___________

4. ACKNOWLEDGEMENT
We would like to express our profound sense of gratitude to all for having helped us in
completing this dissertation. We would like to express our deep felt gratitude and sincere
thanks to our guide Dr.R Govinda Rao, Professor/ Associate professor/Assistant Professor,
Department of Metallurgical Engineering, Gandhi Institute of Engineering & Technology,
Gunupur for his skilful guidance, timely suggestions and encouragement in completing this
project.
We are highly obliged to our project coordinator Mr. Siva Raju, Professor, for having
extended his affable guidance, constant supervision and encouragement throughout the
progress of this project, which helped us to complete it within the stipulated time.
We would like to express our sincere thanks to Prof. (Dr.) Ajit KumarSenapati, Associate
Professor and Head of Department of Metallurgical Engineering, for providing the necessary
facilities for the successful completion of this work.
We wish to acknowledge the support received from our Principal, Dean and management
during the course of this project.
Last but not least, we wish to thank our Teaching& Non-teaching Staff, our parents
and all our friends for their constant moral support, co-operation and encouragement during
this period.
i

5. ABSTRACT
The Al 7075 alloy is a very useful material because of its mechanical properties i.e. low
density, high strength, moderate ductility and toughness. Due to these properties, this alloy is
mainly used for highly stressed structural parts. This material has a wide range of application
such as aircraft fittings, gears and shafts, fuse parts, meter shafts and gear, missile parts ,
regulating valve parts, worm gears, keys and various other parts of commercial aircrafts and
aerospace vehicles.
The main objective of our work is to improve the mechanical properties such as hardness,
Tensile strength, Compressive strength of Aluminum based Composite, and its relation with
processing of the Alumina particulate (Al2O3) as reinforced in Fly ash matrix. Aluminum
7075 alloy is chosen as matrix alloy, in which Aluminum is the base element. The work has
been proposed for Hardness test, Compression test and Tensile test.
Mechanical properties like Tensile test, Hardness test are conducted on Al 7075 reinforced
with Fly ash . These reinforcements provide comparatively high Strength and Hardness.
Ii

6. CONTENT
Title Page
ACKNOWNLEDGENENT............................................................................................. i
ABSTRACT...................................................................................................................... ii
LIST OF TABLES............................................................................................................ iii
LIST OF FIGURES.......................................................................................................... iv
CHAPTER -1:
1.1 INTRODUCTION.......................................................................................................1
CHAPTER- 2:
2. LITERATURE REVIEW................................................................................................2
2.1 CHARACTERSTICS....................................................................................................2
2.2 COMPOSITION OF Al 7075........................................................................................2
2.3 PROPERTIES OF Al 7075............................................................................................3
2.4 DEFINATION OF COMPOSITE.................................................................................3
2.5 CLASSIFICATION OF COMPOSITE.........................................................................4
2.6 ALUMINIUM –FLY ASH REINFORCED COMPOSITE..........................................5
2.7 FLY ASH.......................................................................................................................6
2.8 WHY FLY ASH.............................................................................................................7
CHAPTER-3:
3.1 EXPERIMENTAL WORK...........................................................................................8
3.2 HARDNESS TEST........................................................................................................9
3.3 TENSILE TEST............................................................................................................10-12
3.4 COMPRESSION TEST................................................................................................12
CHAPTER-4:
4.1 STRENGTHENING MECHANISM...........................................................................13
4.2 RECOVERY.................................................................................................................13
4.3 RECRYSTALLIZATION............................................................................................13
4.4 GRAIN GROWTH.......................................................................................................14
CHAPTER-5:
5.1 RESULT AND DISCUSSION....................................................................................15
5.2 COMPRESSION TEST RESULTS..............................................................................16-19
5.2.1 COMPOSITE.............................................................................................................16
5.2.2 PURE Al.....................................................................................................................17

7. 5.2.3 Al 6062.......................................................................................................................18
5.2.4 Al 7075.......................................................................................................................19
5.3 TENSILE TEST RESULTS.........................................................................................20-23
5.3.1 PURE Al....................................................................................................................20
5.3.2 Al 6061......................................................................................................................21
5.3.3 Al 7075......................................................................................................................22
5.3.4 COMPOSITE............................................................................................................23
5.4 HARDNESS TEST RESULTS....................................................................................24
5.5 MECHANICAL PROPERTIES..................................................................................24
CHAPTER-6:
CONCLUSION.................................................................................................................25
CHAPTER-7:
REFERENCES.................................................................................................................26

8. LIST OF TABLES
Table Title Page
1 Composition of Al 7075 2
2 Properties of Al 7075 3
3 Tensile test results of Pure Al 20
4 Tensile test results of Al 6061 21
5 Tensile test results of Al 7075 22
6 Tensile test results of Composite 23
7 Hardness test results 24
8 Mechanical properties 24
iii

9. LIST OF FIGURES
Figure Title Page
1 Microstructure of base alloy 7075 2
2 Fly ash 6
3 Laboratory stir casting set up 8
4 Hardness Before testing and After testing 9
5 BrinellHardnss Tester 10
6 Electronic Tensile Testing Machine10
7 Tensile Test Sample 11-12
8 Universial Testing Machine 12
9 Optical microstructure of different metals15
After compression test
10 Load vs. Displacement curve for different 16-19
metals After Compression test
11 Load vs. Displacement curve for different 20-23
metals After Tensile test
Iv

10. CHAPTER 1
1.INTRODUCTION
Conventional monolithic materials have limitations in achieving good combination of
strength, stiffness, toughness and density. To overcome these shortcomings and to meet the
ever increasing demand of modern daytechnology, composites are most promising materials
of recent interest. Metal composites possess significantlyimproved properties including high
specific strength, specific modulus, damping capacity and good wear resistance compared to
unreinforced alloys. There has been an increasing interest in composites containing low
density and low cost reinforcements. Among various discontinuous dispersoids used, fly ash
is one of the most inexpensive and low density reinforcement available in large quantities as
solid waste by-product during combustion of coal in thermal power plants. Hence,
composites with fly ash as reinforcement are likely to overcome the cost barrier for wide
spread applications in automotive and small engine applications. It is therefore expected that
the incorporation of fly ash particles in aluminium alloy will promote yet another use of this
low-cost waste by-product and, at the same time, has the potential for conserving energy
intensive aluminium and thereby, reducing the cost of aluminium products.
Now the days the particulate reinforced aluminium composites are gaining importance
because of their lowcost with advantages like isotropic properties and the possibility of
secondary processing facilitating fabrication of secondary components. Cast aluminium
matrix particle reinforced composites have higher specific strength, specific modulus and
good wear resistance as compared to unreinforced alloys.
In the present work, fly-ash which mainly consists of refractory oxides like silica, alumina,
and iron oxides isused as reinforcing phase. Composite was produced with 10gm to40gm fly-
ash as reinforcing phase. Commercially pure aluminium was also melted and casted. Then
particle size and chemical composition analysis for fly-ash was done. Mechanical, physical
and grain properties of the composite were evaluated and compared with the commercially
pure aluminium. Mechanical properties of composites are affected by the size, shape and
volume fraction of the reinforcement, composite material and reaction at the interface.

11. CHAPTER 2
2. LITERATURE REVIEW
2.1 CHARACTERISTICS
7075 aluminum alloy is perfect for applications where high strength is essential and good
corrosion resistance is less important. It is known to have a high strength to weight ratio and
certain tempers offer decent resistance to stress-corrosion cracking. 7075 is able to match
most steel alloys in terms of strength.
(Fig 1: Microstructure of base alloy 7075)
2.2 COMPOSION OF Al 7075
Table-1 Composition of Al 7075
Material Weight %
Copper 1.53
Chromium 0.20
Magnesium 2.50
Zinc 5.45
Iron 0.20
Manganese 0.25
Silicon 0.30
Titanium 0.16
Aluminum Remaining

12. 2.3 PROPERTIES OF Al 7075
Table-2 Properties of Al 7075
Mechanical properties Values
Hardness – Brinell 94.95
Tensile yield strength 198.9MPa
Elongation at beak 5.40%
Modulus of Elasticity 71.7GPa
Poisson’s Ratio 0.33
Machinability 70%
Shear modulus 26.9GPa
Shear strength 331Mpa
2.4 Definition of composite material:
The composite material can be defined as the system of material consisting of a mixture of
combination of two or more micro constituents insoluble in each other and differing in form
and or in material composition .These materials can be prepared by putting two or more
dissimilar material in such way that they function mechanically as a single unit. The
properties of such materials differ from those of their constituents. These materials may have
a hard phase embedded in a soft phase or vice versa. Normally in the composite material have
a hard phase in the soft ductile matrix where the hard phase act as a reinforcing agent
increase the strength and modulus, and soft phase act as matrix material. The requirement for
satisfying the above mentioned condition is
a. The composite material has to be man-made
b. The composite material must be a combination of at least two chemically distinct
materials with an interface separating the components.
c. The properties of composite should be three dimensionally combined.

13. 2.5 Classification of Composites
On the basis of Matrix composite can be classified in the following groups:
a) Polymer-matrix composites (PMC)
The most common matrix materials for composites are polymeric. Polyester and viny esters
are the most widely used and least expensive polymer resins. These matrix materials are
basically used for fiber glass reinforced composites. For mutations of a large number resin
provide a wide range of properties for these materials .The epoxies are more expensive and in
addition to wide range of ranging commercials applications ,also find use in PMCs for
aerospace applications. The main disadvantages of PMCs are their low maximum working
temperature high coefficients of thermal expansion and hence dimensional instability and
sensitivity to radiation and moisture. The strength and stuffiness are low compared with
metals and ceramics.
b) Metal-matrix composites (MMC)
The matrix in these composites is a ductile metals .These composites can be used at higher
service temperature than their base metal counterparts. These reinforcements in these
materials may improve specific stuffiness specific strength, abrasion resistance, creep
resistance and dimensional stability. The MMCs is light in weight and resist wearand thermal
distortion, so it mainly used in automobile industry. Metal matrix composites are much more
expensive those PMCs and, therefore, their use is somewhat restricted. [9, 10]
c) Ceramic-matrix composites (CMC)
One of the main objectives in producing CMCs is to increase the toughness. Ceramics
materials are inherent resistants to oxidation and deterioration at elevated temperatures; were
it not for their disposition to brittle fracture, some of these materials would be idea candidates
for use in higher temperature and serve-stress applications, specifically for components in
automobile an air craft gas turbine engines .The developments of CMCs has lagged behind
mostly for remain reason, most processing route involve higher temperature and only
employed with high temperature reinforcements.
On the basics of reinforcement can be classified into three types:
a) Particle reinforced composites
Particulate reinforcements have dimensions that are approximately equal in all directions
.The shape of the reinforcing particles may be spherical, cubic, platelet or any regular or
irregular geometry. These composite can classified under two sub groups :
(i) Large particle composites
(ii) Dispersion strengthened composites

14. b) Fiber reinforced composites
A fibrous reinforcement is characterized by its length being much greater than its cross-
sectional dimension .However the ratio of length to the cross sectional dimension know as the
aspect ratio, can vary considerably .In single layer composite long fibers with high aspect
ratios give that are called continuous fiber reinforced composites whereas discontinuous fiber
reinforced composites are fabricated using short fibres of low aspect ratio .The orientation of
the discontinuous fibres may be random or preferred .The frequently encountered preferred
orientation in the case of continuous fibre composite is termed unidirectional and the
corresponding random situation can be approximated to by bidirectional woven
reinforcement.
2.6 Aluminium -fly ash particulate reinforced composite
M. Ramachandra K. Radhakrishna has worked on the Effect of reinforcement of fly ash on
sliding wear, slurry erosive wear and corrosive behavior of aluminium matrix composite. Al
(12 wt% Si) as matrix material and up to 15 wt% of fly ash particulatecomposite was
fabricated using the stir casting rote and came forward into following conclusions
Fly ash improves abrasive wear resistance (20-30%) of Al. and reduces the coefficient of
Friction.
Increase in normal load and sliding velocity increases magnitude of wear and frictional
force.Different wear mechanisms were studied under varying different parameter such as
normal load, % of fly ash content and sliding velocity.
Four different mechanisms are found that are abrasion, oxidation, delamination, thermal
softening and adhesion.Corrosion resistance of reinforced composite has decreased with
increase in flyash content.
Sudarshan, M.K. Surappa havesynthesized A356 Al–fly ash particle composites .They
studied mechanical properties and dry sliding wear and come into brief idea that
Fly ash with narrow size range (53–106μm) show better properties compared with the wider
size range (0.5–400μm) particles.
The damping capacity of composite increases with the increase in volume fraction of fly
ash.Fracture surface of composites show mixed mode (ductile and brittle) fracture.
The 6%of fly ash particles into A356 Al alloy shows low wear rates at low loads (10 and 20
N)while12% of fly ash reinforced composites show lower wear rates compared to the
unreinforced alloy in the load range 20–80 N.

15. The types of wear dominant in unreinforced alloy are adhesive wear, whereas abrasive wear
is predominant in composites. At higher load, subsurface delamination is the main
mechanism in both the alloy as well in composites.
R.Q. Guoa and P.K. Rohatgi, while studding the changes of chemical reaction between the Al
and the fly ash during synthesis or reheating of fly ash found out that
The chemical reactions do occur between the fly ash an Al melts. The SiO2and Fe2O3
present in the fly ash is reduced to Si and Fe .The melt oxidized to Al2O3.
2.7 FLY ASH
Fly ash is one of the residues generated in the combustion of coal. It is an industrial
byproduct recovered from the flue gas of coal burning electric power plants. Depending upon
the source and makeup of the coal being burned, the components of the fly ash produced vary
considerably, but all fly ash includes substantial amounts of silica (silicon dioxide, SiO2)
(both amorphous and crystalline) and lime (calcium oxide, CaO). In general, fly ash consists
of SiO2, Al2O3, and Fe2O3 as major constituents and oxides of Mg, Ca, Na, K etc. as minor
constituent. Fly ash particles are mostly spherical in shape and range from less than 1 μm to
100 μm with a specific surface area, typically between 250 and 600m2/kg. The specific
gravity of fly ash vary in the range of 0.6-2.8 gm/cc. Coal fly ash has many uses including as
a cement additive, in masonry blocks, as a concrete admixture, as a material in lightweight
alloys, as a concrete aggregate, in flow able fill materials, in roadway/runway construction, in
structural fill materials, as roofing granules, and in grouting. The largest application of fly ash
is in the cement and concrete industry, though, creative new uses for fly ash are being
actively sought like use of fly ash for the fabrication of MMCs.
(Figure 2: Fly Ash)

16. 2.8 WHY FLY ASH
1. The preference to use fly ash as a filler or reinforcement in metal and polymer matrices is
that fly ash is a byproduct of coal combustion, available in very large quantities at very low
costs since much of this is currently land filled. Currently, the use of manufactured glass
micro spheres has limited applications due mainly to their high cost of production. Therefore,
the material costs of composites can be reduced significantly by incorporating fly ash into the
matrices of polymers and metallic alloys.
2. The high electrical resistivity, low thermal conductivity and low density of fly-ash may be
helpful for making a light weight insulating composites.
3. Fly ash as a filler in Al casting reduces cost, decreases density and increase hardness,
stiffness, wear and abrasion resistance. It also improves the maintainability, damping
capacity, coefficient of friction etc. which are needed in various industries like automotive
etc.
4. As the production of Al is reduced by the utilization of fly ash. This reduces the generation
of green house gases as they are produced during the bauxite processing and alumina
reduction.

17. CHAPTER 3
3.1 EXPERIMENTAL WORK
Following steps are carried out in our experimental work
1. Material selection
2. Composite preparation
3. Testing
3.1 Hardness test
3.2 Tensile test
3.3 Compression test
Material selection
The Al 7075 alloy (matrix material), reinforcement Fly ash were used for fabrication of
MMCs, Al 7075,Al 6061 and pure Al.
Composite Preparation
The aluminum fly ash metal matrix composite was prepared by stir casting route. For this we
took pure aluminum and desired amount of fly ash particles. The fly ash particle was
preheated to 300ᵒC for three hour to remove moisture. Commercially pure aluminum was
melted in a resistance furnace. The melt temperature was raised up to 720ᵒC and then the melt
was stirred. The melt temperature was maintained 700ᵒC during addition of fly ash particles.
The melt with reinforced particulates were poured into the preheated permanent metalicmold.
The pouring temperature was maintained at 680ᵒC.The melt was then allow to solidify the
moulds. Magnesium and silicon were added to increase the wettability of fly ash particles.
(Fig 3 Laboratory stir casting set up)

18. 3.2 Hardness test
The Brinell hardness test method as used to determine Brinell hardness is defined in ASTM
E10. Most commonly it is used to test materials that have a structure that is too coarse or that
have a surface that is too rough to be tested using another test method.Brinell hardness is
determined by forcing a hard steel or carbide sphere of a specified diameter under a
specifiedload into the surface of a material and measuring the diameter of the indentation left
after the test. The Brinellhardness number, or simply the Brinell number, is obtained by
dividing the load used, in kilograms, by the actual surface area of the indentation, in square
millimeters. The result is a pressure measurement, but the units are rarely stated.
The BHN is calculated according to the following formula:
Where
BHN = the Brinell hardness number
P = the imposed load in kg
D = the diameter of the spherical indenter in mm
d= diameter of the resulting indenter impression in mm
Fig 4(a)Fig 4(b)
Fig 4(a) Before testing and (b) After testing

19. (Fig 5Brinell hardness tester)
3.3 Tensile test
Tensile testing, also known as tension testing, is a fundamental materials science test in
which a sample is subjected to uni-axial tension untill failure. The results from the test are
commonly used to select a material for an application, for quality control, and to predict how
a material will react under other types of forces. Properties that are directly measured via a
tensile test are ultimate tensile strength, maximum elongation & reduction in area. The tensile
specimens of diameter 6 mm and gauge length 37 mm were machined from the cast
composites with the gauge length of the specimen parallelto the longitudinal axis of the
castings.
Fig 6 Electronic Tensile Testing Machine (Tenson Meter )

20. Fig 7(a)Before testing
Fig 7(b)After testing (Al 7075)
Fig 7(c)After testing (Al 6061)
Fig 7(d)After testing (Pure Al)

21. Fig 7(e) After testing(composite)
3.4 Compression test
The compression test specimens were machined to have cylindrical shape with 10 mm
diameter and 10 mm height. Isothermal compression tests at constant strain rates and constant
temperatures were conducted. The maximum compression equivalent strain of 0.2 was
achieved in the test. Before beginning the test, the specimens were held in the die for some
minutes to allow the material to reach steady state. The temperature was measured using
thermocouples. Carbon powder was used as a lubricant to decrease the effect of friction and
barreling. The deformation temperature and strain rate were automatically controlled by the
machine control unit. Some specimens were subjected to the cold compression test at room
temperature and constant cross head speed. The specimens were subjected to this test to
investigate the anisotropy behavior by measuring the flow stress curve at room temperature,
and by measuring two perpendicular diameters on the specimen’s cross section.
( Fig 8 Universial testing machine)

22. CHAPTER 4
4.1 STRENGTHENING MECHANISM
a.Recovery
b.Recrystallization
c.Grain growth
4.2 RECOVERY
It is a low temperature phenomena which result in the restoration of physical properties.
In this region, no appreciable change in microstructure is observed.
The grains remain distorted and hence mechanical properties such as hardness, tensile
strength and ductility do not change appreciably.
Negligible effect on hardness.
Release internal stresses.
Reduce the number of dislocation.
However, due to heating, some imperfection like vacancies and interstitialcies exiting in the
slip bands may get eliminated.
During recovery, physical properties of the cold worked material are restored without any
observable change in microstructure.
There is some reduction, though not substantial, in dislocation density as well apart from
formation of dislocation configurations with low strain energies.
4.3 RECRYSTALLIZATION
In this region old distorted grains are replaced by new stress free grain, strain free grains by a
process of neucleation and growth This occurs by a recrystallization process.
The microstructure at the end of recrystallization process is very much similar to the original
structure i.e. similar to the structure prior to cold work.
The grains become equiaxed and the dislocation density gets reduced to a value
characteristics of strain free metal.
Due to change in microstructure, all the mechanical properties are changed and the internal
stresses are reduced.
It involves replacement of cold-worked structure by a new set of strain-free,approximately
equi-axed grains to replace all the deformed crystals.
The recrystallization temperature is strongly dependent on the purity of a material.
Pure materials may recrystallize around 0.3Tm, while impure materials may recrystallise
around 0.4Tm, where Tm is absolute melting temperature of the material.

23. 4.4GRAIN GROWTH
If a completely recrystallized material is heated to a higher temperature and kept for a longer
time at the annealing temperature, it will show that the size of the grain will increases.
It affects on the ductility of the material i.e. the ductility will be improved.
During this type of growth, some grains grow abnormally at the expense of the surrounding
recrystallized grains.
This occurs by rapid migration of grain boundaries of few of the primary recrystallized grains
with a results of formation of very large secondary grains.
The driving force for the grain growth is the reduction in the grain boundary surface energy.

24. CHAPTER 5
5.1 RSEULTS AND DISCUSSION
Optical microstructure of different metals
Fig 9(a)After compression(Al 7075) Fig 9(b)After compression(pure Al)
Fig 9(C)After compression(Al 6061)Fig 9(d)After compression(composite)

25. 5.2 Compression test results
5.2.1.Composite
( Fig 10 (a)Load vs. Displacement)

26. 5.2.2 Pure Al
( Fig 10 (b)Load vs. Displacement)

27. 5.2.3 Al 6061
( Fig 10 (c)Load vs. Displacement)

28. 5.2.4 Al 7075
( Fig 10(d) Load vs. Displacement)

29. 5.3 Tensile test results
5.3.1 Pure Al
Table -3
High Limit : 19614 N Low Limit : 196 N
Cross Sec Area : 28.40 SQ MM Sample Length : 38.0 MM
Selected Load Cell : 20 KN Test Speed : 0.2 MM /MIN
Peak Load : 1588 N At Length : 6.3 MM Peak Disp. : 16.6 %
Break Load : 107 N At Length : 8.6 MM Break Disp. : 22.6 %
Ten/Cmp Stress : 55.9 N / SQ MM U.T.S. : 55.9 N / SQ MM
Fig 11(a) Stress vs. Strain
Fig 11(b) Load vs. Displacement
0
10
20
30
40
50
60
0.00 0.04 0.09 0.13 0.18 0.22
StressInN/Sq.MM
Strain
0
200
400
600
800
1000
1200
1400
1600
1800
0.00 1.70 3.40 5.10 6.80 8.50
LoadInN
Displacement In mm

30. 5.3.2Al 6061
Table-4
High Limit : 19614 N Low Limit : 196 N
Cross Sec Area : 28.40 SQ MM Sample Length : 38.0 MM
Selected Load Cell : 20 KN Test Speed : 0.2 MM /MIN
Peak Load : 5060 N At Length : 3MM Peak Disp. : 6.8 %
Break Load : 5060 N At Length : 3MM Break Disp. : 8.1 %
Ten/Cmp Stress : 178.2 N / SQ MM U.T.S. : 178.2 N / SQ MM
Fig 12(a) Stress vs. Strain
Fig 12(b) Load vs. Displacement
0
20
40
60
80
100
120
140
160
180
200
0.00 0.01 0.03 0.04 0.05 0.07
StressInN/Sq.MM
Strain
0
200
400
600
800
1000
1200
1400
1600
1800
0.00 1.70 3.40 5.10 6.80 8.50
LoadInN
Displacement In mm

31. 5.3.3Al 7075
Table-5
High Limit : 19614 N Low Limit : 196 N
Cross Sec Area : 28.40 SQ MM Sample Length : 37.0 MM
Selected Load Cell : 20 KN Test Speed : 0.2 MM /MIN
Peak Load : 5649 N At Length : 2.1 MM Peak Disp. : 5.7 %
Break Load : 5649 N At Length : 2.5 MM Break Disp. : 6.8 %
Ten/Cmp Stress : 198.9 N / SQ MM U.T.S. : 198.9 N / SQ MM
Fig 13(a) Stress vs. Strain
Fig 13(b) Load vs.Displacement
0
50
100
150
200
250
0.00 0.01 0.02 0.02 0.03 0.04
StressInN/Sq.MM
Strain
0
1000
2000
3000
4000
5000
6000
0.00 0.30 0.60 0.90 1.20 1.50
LoadInN
Displacement In mm

32. 5.3.4Composite
Table-6
High Limit : 19614 N Low Limit : 196 N
Cross Sec Area : 28.40 SQ MM Sample Length : 37.0 MM
Selected Load Cell : 20 KN Test Speed : 0.2 MM /MIN
Peak Load : 12004N At Length : 1.4 MM Peak Disp. : 3.7 %
Break Load : 10023 N At Length : 1.4 MM Break Disp. : 3.7 %
Ten/Cmp Stress : 422.7 N / SQ MM U.T.S. : 422.7 N / SQ MM
Fig 14(a) Stress vs. Strain
Fig 14(b)Load vs. Displacement
0
50
100
150
200
250
300
350
400
450
0.00 0.02 0.03 0.05 0.06 0.08
StressInN/Sq.MM
Strain
0
2000
4000
6000
8000
10000
12000
14000
0.00 0.60 1.20 1.80 2.40 3.00
LoadInN
Displacement In mm

33. 5.4 Hardness test
Table-7
Materials BHN
Pure Al 29.55
AL 6061 41.53
Al 7075 94.95
Composite 138.21
5.5 Mechanical Properties
Table-8
Sample Hardness Tensile length %of
Elongation
% of Reduction
In Area
Pure Al 29.55 55.9 18.42 11.55
Al 6061 41.53 178.2 13.51 10.52
Al 7075 94.95 198.9 5.40 5.12
Composite 138.21 422.7 2.70 2.63

34. CHAPTER 6
CONCLUSIONS
Here we successfully fabricated the Al 7075-Fly Ash with proper distribution of ash particles
all over the specimen. We have drawn various conclusions from the various calculations
based on the diff. experimental testes:
From the study it is concluded that we can use fly ash for the production of composites and
can turn industrial waste into industrial wealth. This can also solve the problem of storage
and disposal of fly ash
Addition of magnesium and silicon improves the wettability of fly ash with aluminium melt
and thus increases the retention of the fly ash in the composite
Hardness of commercially aluminium is increased from 95BHN to 138BHN with addition of
fly ash and magnesium.
The Ultimate tensile strength has improved with increase in fly ash content. Where as
ductility has decreased with increase in fly ash content.
The effect of increased reinforcement on the wear behavior of the MMCs is to increase the
wear resistance and reduce the coefficient of friction. The MMCs exhibited better wear
resistance due to its superior load bearing capacity
The density of the composites decreased with increasing ash content. Hence these light
weight composites can be used where weight of an object maters as like in the aero and space
industries.
From the above results we find the Composite having an good toughness, hardness, tensile
strength and alsohaving the low density comparatively alloys . So that these composites could
be used in those sectors where light weight and good mechanical properties are required as
like in automobile and space industries

35. CHAPTER 7
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36. Thank you