“to study the effect of heat treatment processes on the properties of aluminum 6063 alloy’’

7/27/2019 To study the effect of heat treatment processes on the properties of Aluminum 6063 alloy

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A project report

On

To study the effect of heat treatment processes on the

properties of Aluminum 6063 alloy

Submitted for partial fulfillment of award of

BACHELOR OF TECHNOLOGY

Degree

In

Mechanical Engineering

By

Navneet Verma 0713340063

Bhuvneshwar Prasad Panchal 0713340029

Nikhil Kumar Singh 0713340064

Ajay Kumar 0713340003


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Name of guide

Mr. Sandeep Chauhan

MECHANICAL ENGINEERING DEPARTMENT

NOIDA INSTITUTE OF ENGINEERING & TECHNOLOGY

Greater Noida

DECLARATION

We hereby declare that this submission is our own work and that, to the best of

our knowledge and belief, it contains no material previously published or written

by another person nor material which to a substantial extent has been accepted

for the award of any other degree or diploma of the university or other institute

of higher learning, except where due acknowledgment has been made in the text.

Bhuvneshwar Prasad Panchal

Navneet Verma


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Nikhil Kumar Singh

Ajay Kumar

CERTIFICATE


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Certified that Navneet Verma, Bhuvneshwar Prasad

Panchal, Ajay Kumar, Nikhil Kumar Singh have carried

out the research work presented in this project entitled To

study the effects of heat treatment processes on the

properties of Aluminum 6063 alloy for the award of

Bachelor Of Technology Degree from Uttar Pradesh

Technical University, Lucknow under my supervision. The

project embodies result of original work and studies carried

out by Student himself and the contents of the project do not

form the basis for the award of any other degree to the

candidate or to anybody else.

Mr. Sandeep Chauhan

Sr. Lecturer

NIET, Gr.Noida

Date: June 2011


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ACKNOWLEDGEMENT

I believe that hard work is the only way to success to achieve something

worthy.

With feeling of immense gratitude and respect, I extend my deep sense of

gratitude to thank my guide Mr. SANDEEP CHAUHAN for their continuous

support throughout this work. Their incredulous guiding spirit and helping handat every step of my project has led to its successful completion.

This project was a learning experience for me. Workings in different labs

provide a real time experience of engineering. & technology being used,

currently, in manufacturing industry.

Finally I would like to thank Mr.Mahipal without their help this project would

not have been possible and their support during this period has been inspired me

to accomplish it.

Bhuvneshwar Prasad Panchal (0713340029)

Ajay Kumar (0713340003)

Navneet Verma (0713340063)

Nikhil Kumar Singh (0713340064)


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TABLE OF CONTENTS

Declaration iCertificate iiAcknowledgement iiiTable of Contents ivList of Figure vList of Table viAbstract

Chapter 1- Introduction 01-19

1.1 Introduction of Heat Treatment 01

1.1.1.Stages Of Heat Treatment And Its Purposes 03

1.2 The Objects Of Heat Treating Aluminium And Its Alloys 05

1.3. Classification Of Heat Treatment 06

1.4. Tempering 07

1.5. Annealing 071.5.1. Objectives Of Annealing 081.5.2. Stages Of Annealing 08

1.6. Normalizing 08

1.6.1. Objectives Of Normalizing 09

1.7. Hardening 091.7.1. Objectives Of Hardening 10

1.8. Heat Treatment: Capabilities And Limitations 10

1.9. Introduction Of Aluminium 11


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1.9.1. Characteristics 121.9.2. Applications 131.9.3. Aluminium Alloys 14

1.9.3.1. Aluminium Alloys In Structural Applications 151.9.3.2. Aluminium6063 Alloy 161.9.3.3. Chemical Composition Of Aluminium6063 Alloy 171.9.3.4. Physical Properties 171.9.3.5. Mechanical Properties 17

1.10. Important Mechanical Properties 18

Chapter 2- Literature Review 20-23

2.1. Literature Review 21

Chapter 3- Methodology Of Test Performed 24-29

3.1. Methodology Of Project 25

3.2. Test Performed On Aluminium 6063 Alloy 263.2.1. Tensile Test 26

3.2.1.1. Tensile Test Specimen 26

3.2.2. Izod Impact Test 27

3.2.3. Charpy Impact Test 28

3.2.4. Rockwell Hardness Test 28

Chapter 4- Results And Analysis 30-44

4.1. Test Performed 314.1.1. Tensile Test 31

4.1.2. Impact Test By Izod Method 374.1.3. Impact Test By Charpy Method 39

4.1.4. Rockwell Hardness Test 42

4.2. Microstructures Of Aluminium 6063 Alloy 44

Chapter 5- Conclusion 45


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5.1. Conclusion 46

5.2. Future Scope Of Aluminium 6063 Alloy 46

References 47Appendix 1 48

Appendix 2 50

LIST OF FIGURES

S.No. Title Page No.

Fig 4.1 Tensile Test Specimen 32

Fig 4.2 Izod Test Specimen 38

Fig 4.3 Charpy Test Specimen 40

Fig 5.1 Microstructure After Quenching 44

Fig 5.2 Microstructure After Normalizing 44

Fig 5.3 Microstructure After Annealing 44


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LIST OF TABELS

S.No. Title Page No.

4.1 Tensile Test Table Before Heat Treatment 31

4.2 Tensile Test Table After Normalizing 32

4.3 Tensile Test Table After Quenching 34

4.4 Tensile Test Table After Annealing 35

4.5 Izod Impact Test Table Before Heat Treatment 37

4.6 Izod Impact Test Table After Quenching 38

4.7 Izod Impact Test Table After Normalizing 39

4.8 Izod Impact Test Table After Annealing 39

4.9 Charpy Impact Test Table Before Heat Treatment 40

4.10 Charpy Impact Test Table After Quenching 41


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4.11 Charpy Test Table After Normalizing 41

4.12 Charpy Test Table After Annealing 42

4.13 Rockwell Hardness Test Table Before Heat Treatment 42

4.14 Rockwell Hardness Test Table After Quenching 43

4.15 Rockwell Hardness Test Table After Normalizing 43

4.16 Rockwell Hardness Test Table After Annealing 43

ABSTRACT

Heat treatment processes for aluminium are precision processes. Based on the objectives of

this research, precipitate free zones in the aluminium alloy 6063 actually give bad effect to the

mechanical properties of that alloy. The mechanical properties of the aluminium alloy should

be altering properly to improve their behavior using precipitation hardening which one of the

heat treatment types. Precipitation hardening is the most suitable heat treatment that should

use to minimize the precipitate free zones in the microstructure of the aluminium alloy 6063.

In the precipitation hardening process, the thermal and temperature condition is under control


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with high precision to ensure the transformation of the aluminium alloy structure is in good

condition and supervision limit. The samples of the material are placed in the furnace to make

a heat treating process and then quench it in the water for quenching medium. The material

testing that had been applied is based on hardness, impact and microstructure analysis. The

purpose of the hardness testing are to find out the hardness reading for all the samples that

used to look the wear resistance effect that occur after make a heat treating process to the

aluminium alloy 6063. From the impact test, the purposes are to know impact 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 narrow evaluation of precipitate free zones in the microstructure of

aluminium alloy after make a precipitation hardening processes. From the data and result thatalready determined, it shown the positive result based on objectives and scope of this project.

CHAPTER -1


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INTRODUCTION

1.1 INTRODUCTION OF HEAT TREATMENT

Heat treatment is a group of industrialandmetal working processesused to alter thephysical, and sometimeschemical, properties of a material. The most common application is

metallurgical. Heat treatments are also used in the manufacture of many other materials, such

as glass. Heat treatment involves the use of heating or chilling, normally to extreme

temperatures, to achieve a desired result such as hardening or softening of a material. Heat

treatment techniques include annealing, case hardening, precipitation strengthening,

tempering and quenching. It is noteworthy that while the term heat treatment applies only to

processes where the heating and cooling are done for the specific purpose of altering

properties intentionally, heating and cooling often occur incidentally during other

manufacturing processes such as hot forming or welding.

Metallic materials consist of a microstructure of small crystals called "grains" or

crystallites. The nature of the grains (i.e. grain size and composition) is one of the most
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effective factors that can determine the overall mechanical behavior of the metal. Heat

treatment provides an efficient way to manipulate the properties of the metal by controlling

rate ofdiffusion, and the rate of cooling within the microstructure.

There are two mechanisms that may change an alloy's properties during heat

treatment. The martensite transformation causes the crystals to deform intrinsically. The

diffusion mechanism causes changes in the homogeneity of the alloy.

The crystal structure consists of atoms that are grouped in a very specific arrangement,

called a lattice. In most elements, this order will rearrange itself, depending on conditions like

temperature and pressure. This rearrangement, called allotropy or polymorphism, may occur

several times, at many different temperatures for a particular metal. In alloys, thisrearrangement may cause an element that will not normally dissolve into the base metal to

suddenly become soluble, while a reversal of the allotropy will make the elements either

partially, or completely insolubles

1.1.1. STAGES OF HEAT TREATMENT AND ITS PURPOSES

The term heat treatment for aluminium alloys is frequently restricted to the specific

operations employed to increase strength & hardness of the precipitation-hardenable wrought

and cast alloys. Heat Treatment- the term heat treatment may be defined as an operation or a

combination of operations, involving the heating and cooling of a metal or an alloy in the

solid state for the purpose of obtaining certain desirable conditions or properties without

change in chemical composition. These usually are referred to as the heat treatable alloys to

distinguish them from those alloys in which no significant strengthening can be achieved by

heating and cooling. Heat treating in its broadest sense refers to any of the heating and cooling

operations are performed for the purpose of changing the mechanical properties, metallurgical

structure, or the residual stress state of the metal product .

Heat treatment applied to aluminium and its alloys are preheating or homogenizing to

reduce chemical segregation of cast structures and to improve material workability. Annealing
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to soften strain hardened and heat treated alloy components to relieve stresses and to

stabilize properties and dimensions. Precipitation (age-hardening) heat treatment to provide

hardening by precipitation of constituents from solid solution. Solution heat treatment to

improve mechanical properties by putting alloying elements into solution.

Heat treatment is a collection through may processes such as Annealing, Stress relief,

Quenching, Tempering, normalizing and ageing. All the different heat treatment process

consists the following three stages-.

1- Heating of the material.

2- Hold the temperature for a time (soaking time).

3- Cooling usually to room temperature (Normalizing).

However the temperature and time for the various processes is dependent on the material

mechanism controlling the wanted effect. The purpose of heat treatment is to achieve one or

more of the following object-

To increase the hardness of metals.

To relieve the stresses set up in the material after hot or cold working.

To improve Machinability.

To soften the metal.

To modify the structure of the material to improve its electrical and magnetic

properties.

To change the grain size.

To increase the qualities of the metal to provide better resistance to heat, corrosion and

wear.

Improve ductility and toughness.


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Pure aluminum is too soft for most structural applications and therefore is usually

alloyed with several elements to improve its corrosion resistance, inhibit grain growth and of

course to increase the strength. The optimum strengthening of aluminum is achieved by

alloying and heat treatments that promote the formation of small, hard precipitates which

interfere with the motion of dislocations. Aluminum alloys that can be heat treated to form

these precipitates are considered heat treatable alloys. Pure aluminum is not heat treatable

because no such particles can form while many heat treatable aluminum alloys are not

wieldable because welding would destroy the microstructure produced by careful heat

treatment.

Virtually all heat treatable aluminum alloys are strengthened by precipitation

hardening. Precipitation hardening involves raising the temperature of the alloy into the single

phase region so that all of the precipitates dissolve. The alloy is then rapidly quenched to form

a supersaturated solid solution and to trap excess vacancies and dislocation loops which can

later act as nucleation sites for precipitation. The precipitates can form slowly at room

temperature (natural aging) and more quickly at slightly elevated temperatures, typically

100C to 200C (artificial aging). The degree of hardening obtained depends on the size,

number and relative strength of the precipitates. These factors are determined by the

composition of the alloy and by the tempering temperature and tempering time.

Proper heat treating requires precise control over temperature, the amount of time that

an alloy remains at a certain temperature, and in the cooling rates of the particular technique.

With the exception of stress-relieving, tempering, and aging, most heat treatments

begin by heating an alloy beyond the upper transformation (A3) temperature. The alloy will

usually be held at this temperature long enough for the heat to completely penetrate the alloy,

thereby bringing it into a complete solid solution. Since a smaller grain size usually enhances

mechanical properties, such as toughness, shear strength and tensile strength, these metals are

often heated to a temperature that is just above the upper critical temperature, in order to

prevent the grains of solution from growing too large. For instance, when steel is heated

above the upper critical temperature, small grains of austenite form. These grow larger as

temperature is increased. When cooled very quickly, during a martensite transformation, the
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austenite grain size directly affects the martensitic grain size. Larger grains have large grain-

boundaries, which serve as weak spots in the structure. The grain size is usually controlled to

reduce the probability of breakage.

The diffusion transformation is very time dependent. Cooling a metal will usually

suppress the precipitation to a much lower temperature. Austenite, for example, usually only

exists above the upper critical temperature. However, if the austenite is cooled quickly

enough, the transformation may be surpressed for hundreds of degrees below the lower

critical temperature. Such austenite is highly unstable and, if given enough time, will

precipitate into various microstructures of ferrite and cementite. The cooling rate can be used

to control rate of grain growth or can even be used to produce partially martensitic

microstructures. However, the martensite transformation is time-independent. If the alloy is

cooled to the martensite transformation temperature before other microstructures can fully

form, the transformation will usually occur at just under the speed of sound.

1.2. THE OBJECTS OF HEAT TREATING ALUMINIUM ALLOYS

Speaking very generally, there are two principal purposes in view when aluminium

and its alloys are industrially heat treated. These are broadly:-

(i) Strengthening or hardening and

(ii) Annealing or softening

There are other objects in subjecting aluminium and its alloys to heat treatments and

these include the alteration of electrical or corrosion properties, the release of casting stresses

and the admission of permanent growth in , for example, pistons; these latter objects are

however of minor importance as compared with the two main objectives indicated above.

1.3. CLASSIFICATION OF HEAT TREATMENT

Various types of heat treatment processes may be classified as follows:-


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1. Tempering

a) Austempering

b) Mar tempering

c) Temperature based

i) Low temperature tempering

ii) Medium temperature tempering

iii) High temperature tempering

2. Annealing

a) Process annealing b) Full annealing

c) Spheroids annealing d) Diffusion annealing

3. Normalizing

4. Hardening

a) Case hardening (or carburizing) b) Flame hardening

c) Induction hardening d) Age hardening

e) Cyaniding e) Nitriding

1.4 TEMPERING

Tempering is a heat treatment technique for metals, alloys and glass. In steels,

tempering is done to "toughen" the metal by transforming brittle martensite orBainite into a

combination of ferrite and cementite or sometimes tempered martensite. Precipitation

hardening alloys, like many grades of aluminum and super alloys are tempered to precipitate
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intermetallic particles which strengthen the metal. Tempering is accomplished by a controlled

reheating of the work piece to a temperature below its lower critical temperature.

The brittle martensite becomes tough and ductile after it is tempered. Carbon atomswere trapped in the austenite when it was rapidly cooled, typically by oil or water quenching,

forming the martensite. The martensite becomes strong after being tempered because when

reheated, the microstructure can rearrange and the carbon atoms can diffuse out of the

distorted body-centered-tetragonal (BCT) structure. After the carbon diffuses, the result is

nearly pure ferrite with body-centered structure.

In metallurgy, there is always a trade-off between strengthand ductility. This delicate

balance highlights many of the subtleties inherent to the tempering process. Precise control of

time and temperature during the tempering process are critical to achieve a metal with well

balanced mechanical properties.

1.5. ANNEALING

Annealing, in metallurgy and materials science, is a heat treatment wherein a material

is altered, causing changes in its properties such as strength and hardness. It is a process that

produces conditions by heating to above the recrystallization temperature, maintaining a

suitable temperature, and then cooling. Annealing is used for inducing ductility, soften

material, relieve internal stresses, refine the structure by making it homogeneous, and

improve cold working properties.

In the cases ofcopper,steel,silver, andbrass, this process is performed by

substantially heating the material (generally until glowing) for a while and allowing it to cool.

Unlikeferrous metalswhich must be cooled slowly to annealcopper, silver and brass can

be cooled slowly in air or quickly by quenching in water. In this fashion the metal is softened

and prepared for further work such as shaping, stamping, or forming.

1.5.1. OBJECTIVES OF ANNEALING

To soften the aluminium so that it may be easily machined or cold worked.
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To refine the grain size & structure to improve mechanical properties like strength &

ductility.

To relieve internal stresses which may have been caused by hot & cold working or byunequal contraction in casting.

To alter electrical magnetic or other physical properties.

To remove gases trapped in the metal during initial casting.

1.5.2. STAGES OF ANNEALING

There are three stages in the annealing process, with the first being the recovery phase,

which results in softening of the metal through removal of crystaldefects (the primary type of

which is the linear defect called a dislocation) and the internal stresses which they cause.

Recovery phase covers all annealing phenomena that occur before the appearance of new

strain-free grains. The second phase is recrystallization, where new strain-free grains nucleate

and grow to replace those deformed by internal stresses. If annealing is allowed to continue

once recrystallization has been completed, grain growth will occur, in which the

microstructure starts to coarsen and may cause the metal to have less than satisfactory

mechanical properties.

1.6. NORMALIZING

Normalizing is a type of heat treatment applicable to ferrous metals only. It differs

from annealing in that the metal is heated to a higher temperature and then removed from the

furnace for air cooling. The purpose of normalizing is to remove the internal stresses induced

by heat treating, welding, casting, forg-ing, forming, or machining. Stress, if not controlled,

leads to metal failure; therefore, before hardening steel, you should normalize it first to ensure

the maximum desired results. Usually, low-carbon steels do not require normalizing;

however, if these steels are normalized, no harmful effects result. Castings are usually

annealed, rather than normalized; however, some castings require the normalizing treatment.
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Table 2-2 shows the approximate soaking periods for normalizing steel. Note that the soaking

time varies with the thickness of the metal. Normalized steels are harder and stronger than

annealed steels. In the normalized condition, steel is much tougher than in any other

structural condition. Parts subjected to impact and those that require maximum toughness

with resistance to external stress are usually normalized. In normalizing, the mass of metal

has an influence on the cooling rate and on the resulting structure. Thin pieces cool faster and

are harder after normalizing than thick ones. In annealing (furnace cooling), the hardness of

the two are about the same.

1.6.1. OBJECTIVES OF NORMALIZING

To refine the grain structure of the aluminum to improve the machaniabilty tensile

strength & structure of weld.

To remove strains caused by cold working processes like hammering rolling, bending

etc which makes the metal brittle & unreliable.

To remove dislocations caused in the internal structure of the aluminum due to hot

working.

To improve certain mechanical & electrical properties.

1.7. HARDENING

The hardening treatment for most steels consists of heating the steel to a set

temperature and then cooling it rapidly by plunging it into oil, water, or brine. Most steels

require rapid cooling (quenching) for hardening but a few can be air-cooled with thesame results. Hardening increases the hardness and strength of the steel, but makes it less

ductile. Generally, the harder the steel, the more brittle it becomes. To remove some of the

brittleness, you should temper the steel after hardening. Many nonferrous metals can be

hardened and their strength increased by controlled heating and rapid cooling. In this case, the

process is called heat treatment, rather than hardening. To harden steel, you cool the metal


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rapidly after thoroughly soaking it at a temperature slightly above its upper critical point. The

approximate soaking periods for hardening steel are listed in table 2-2. The addition of alloys

to steel decreases the cooling rate required to produce hardness. A decrease in the cooling rate

is an advantage, since it lessens the danger of cracking and warping. Pure iron, wrought iron,

and extremely low-carbon steels have very little hardening properties and are difficult to

harden by heat treatment. Cast iron has limited capabilities for hardening. When you cool cast

iron rapidly, it forms white iron, which is hard and brittle. And when you cool it slowly, it

forms gray iron, which is soft but brittle under impact. In plain carbon steel, the maximum

hardness obtained by heat treatment depends almost entirely on the carbon content of the

steel.

To perform hardening process, Al-alloy is heated to a temperature above its critical

range. It is held at this temperature for a considerable time and then allowed to cool by

quenching in water, oil, brine solution.

1.7.1. OBJECTIVES OF HARDENING

To increase the hardness of the metal so that it can resist wear.

To enable it to cut other metals i.e. to make it suitable for cutting tools.

Various factors responsible for hardness in aluminium alloy are the following:

Quenching rate

Work size

1.8. HEAT TREATMENT: CAPABILITIES AND LIMITATIONS

Heat treatments are an established, if obscure, method of disinfesting certain empty

structures and equipment. Since the anticipated phase-out of methyl bromide fumigants,

interest in this non-chemical pest management technique has been growing. Many of the

advantages, disadvantages, considerations, observations, costs and results of using heat to


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disinfest empty food processing and storage structures are situational in reality. Like

fumigation with methyl bromide, successful heat treatments depend upon trained personnel,

careful preparation, employee cooperation, good weather, etc.

Some possible advantages of a heat treatment include the following-

Perceived to be less dangerous than fumigation

Fewer regulations than associated with fumigation

Can monitor and adjust treatment easier than fumigation

More effective than fumigation of a leaky structure

More effective against pathogenic microorganisms

Some possible disadvantages of a heat treatment include the following-

Generally ineffective at penetrating commodities and debris

Significantly more expensive than a methyl bromide fumigation

Exposure period may be longer than for a methyl bromide fumigation

Strong potential for damage to equipment and structure

Less known about actual heat treatments than fumigations

1.9. INTRODUCTION OFALUMINIUM

Aluminium is a silvery white member of theboron group ofchemical elements. It has

the symbol Al and its atomic number is 13. It is not soluble in water under normal

circumstances. Aluminium is the most abundant metal in the Earth's crust, and the third most

abundant element, afteroxygenandsilicon. It makes up about 8% by weight of the Earth's

solid surface. Aluminium is too reactive chemically to occur in nature as a free metal.

Instead, it is found combined in over 270 different minerals. The chief source of aluminium

isbauxiteore.
http://en.wikipedia.org/wiki/Boron_grouphttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Atomic_numberhttp://en.wikipedia.org/wiki/Element_abundancehttp://en.wikipedia.org/wiki/Earthhttp://en.wikipedia.org/wiki/Earthhttp://en.wikipedia.org/wiki/Crust_(geology)http://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Mineralhttp://en.wikipedia.org/wiki/Mineralhttp://en.wikipedia.org/wiki/Bauxitehttp://en.wikipedia.org/wiki/Orehttp://en.wikipedia.org/wiki/Boron_grouphttp://en.wikipedia.org/wiki/Chemical_elementhttp://en.wikipedia.org/wiki/Atomic_numberhttp://en.wikipedia.org/wiki/Element_abundancehttp://en.wikipedia.org/wiki/Earthhttp://en.wikipedia.org/wiki/Crust_(geology)http://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Mineralhttp://en.wikipedia.org/wiki/Bauxitehttp://en.wikipedia.org/wiki/Ore


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Aluminium is remarkable for the metal's low density and for its ability to resist

corrosion due to the phenomenon of passivation. Structural components made from

aluminium and its alloys are vital to the aerospace industry and are very important in other

areas of transportation and building. Its reactive nature makes it useful as a catalyst or

additive in chemical mixtures, including ammonium nitrate explosives, to enhance blast

power.

Despite its prevalence in the environment, aluminium salts are not known to be used

by any form of life. Also in keeping with the element's abundance, it is well toleratedby

plants in soils (in which it is a major component), and to a lesser extent, by animals as a

component of plant materials in the diet (which often contain traces of dust and soil). Soluble

aluminium salts have some demonstrated toxicity to animals if delivered in quantity by

unnatural routes, such as injection. Controversy still exists about aluminums possible long-

term toxicity to humans from larger ingested amounts.

1.9.1. CHARACTERISTICS

Aluminium is a soft, durable, lightweight, ductile and malleable metal with

appearance ranging from silvery to dull gray, depending on the surface roughness.

Aluminium is nonmagnetic and no sparking. It is also insoluble in alcohol, though it can be

soluble in water in certain forms. The yield strength of pure aluminium is 711 MPa, while

aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has

about one-third the density and stiffness of steel. It is easily machined, cast, drawn and

extruded. Corrosion resistance can be excellent due to a thin surface layer of aluminium

oxide that forms when the metal is exposed to air, effectively preventing further oxidation.

The strongest aluminium alloys are less corrosion resistant due to galvanic reactions with

alloyed copper. This corrosion resistance is also often greatly reduced when many aqueous

salts are present, particularly in the presence of dissimilar metals.

Aluminium atoms are arranged in a face-centered cubic (fcc) structure. Aluminium is

one of the few metals that retain full silvery reflectance in finely powdered form, making it an

important component of silver paints. Aluminium mirror finish has the highest reflectance of
http://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Corrosionhttp://en.wikipedia.org/wiki/Passivationhttp://en.wikipedia.org/wiki/Passivationhttp://en.wikipedia.org/wiki/Aluminium_alloyhttp://en.wikipedia.org/wiki/Aluminium_alloyhttp://en.wikipedia.org/wiki/Aerospacehttp://en.wikipedia.org/wiki/Transporthttp://en.wikipedia.org/wiki/Catalysthttp://en.wikipedia.org/wiki/Ammonium_nitratehttp://en.wikipedia.org/wiki/Explosiveshttp://en.wikipedia.org/wiki/Toxicityhttp://en.wikipedia.org/wiki/Ductilityhttp://en.wikipedia.org/wiki/Malleablehttp://en.wikipedia.org/wiki/Malleablehttp://en.wikipedia.org/wiki/Malleablehttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Yield_(engineering)http://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Aluminium_alloyhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Elastic_modulushttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Casting_(metalworking)http://en.wikipedia.org/wiki/Drawing_(metalworking)http://en.wikipedia.org/wiki/Aluminium_oxidehttp://en.wikipedia.org/wiki/Aluminium_oxidehttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Galvanic_cellhttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Cubic_crystal_systemhttp://en.wikipedia.org/wiki/Reflectancehttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Corrosionhttp://en.wikipedia.org/wiki/Passivationhttp://en.wikipedia.org/wiki/Aluminium_alloyhttp://en.wikipedia.org/wiki/Aerospacehttp://en.wikipedia.org/wiki/Transporthttp://en.wikipedia.org/wiki/Catalysthttp://en.wikipedia.org/wiki/Ammonium_nitratehttp://en.wikipedia.org/wiki/Explosiveshttp://en.wikipedia.org/wiki/Toxicityhttp://en.wikipedia.org/wiki/Ductilityhttp://en.wikipedia.org/wiki/Malleablehttp://en.wikipedia.org/wiki/Metalhttp://en.wikipedia.org/wiki/Yield_(engineering)http://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Aluminium_alloyhttp://en.wikipedia.org/wiki/Densityhttp://en.wikipedia.org/wiki/Elastic_modulushttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Casting_(metalworking)http://en.wikipedia.org/wiki/Drawing_(metalworking)http://en.wikipedia.org/wiki/Aluminium_oxidehttp://en.wikipedia.org/wiki/Aluminium_oxidehttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Galvanic_cellhttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Cubic_crystal_systemhttp://en.wikipedia.org/wiki/Reflectance


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any metal in the 200400 nm (UV) and the 3,00010,000 nm (farIR) regions; in the 400

700 nm visible range it is slightly outperformed by tin and silverand in the 7003000 (near

IR) by silver,gold, and copper.

Aluminium is a good thermal and electrical conductor, having 62% the conductivity of

copper. Aluminium is capable of being a superconductor, with a superconducting critical

temperature of 1.2 Kelvins and a critical magnetic field of about 100 gauss (10 milliteslas).

1.9.2.APPLICATIONS

Aluminium is the most widely used non-ferrous metal. Global production of

aluminium in 2005 was 31.9 million tonnes. It exceeded that of any other metal except iron(837.5 million tonnes). Forecast for 2012 is 4245 million tons, driven by rising Chinese

output. Relatively pure aluminium is encountered only when corrosion resistance and/or

workability is more important than strength or hardness. A thin layer of aluminium can be

deposited onto a flat surface by physical vapour depositionor (very infrequently) chemical

vapour deposition or other chemical means to form optical coatings and mirrors. When so

deposited, a fresh, pure aluminium film serves as a good reflector (approximately 92%) of

visible light and an excellent reflector (as much as 98%) of medium and far infrared radiation.

Pure aluminium has a low tensile strength, but when combined with thermo-mechanical

processing, aluminium alloys display a marked improvement in mechanical properties,

especially when tempered. Aluminium alloys form vital components ofaircraft androcketsas

a result of their high strength-to-weight ratio. Aluminium readily forms alloys with many

elements such as copper, zinc,magnesium, manganeseand silicon (e.g., duralumin). Today,

almost all bulk metal materials that are referred to loosely as "aluminium", are actually alloys.

For example, the common aluminium foils and beverage cans are alloys of 92% to 99%aluminium.

Some of the many uses for aluminium metal are in:

Transportation (automobiles, aircraft, trucks, railway cars, marine vessels, bicycles

etc.) as sheet, tube, castings etc.
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Packaging (cans, foil, etc.)

Construction (windows, doors, siding, building wire, etc.)

A wide range of household items, from cooking utensils tobaseball bats, watches.

Street lighting poles, sailing ship masts, walking poles etc. Outer shells of consumer

electronics, also cases for equipment e.g. photographic equipment.

Electrical transmission lines for power distribution

MKM steel and Alnico magnets

Super purity aluminium (SPA, 99.980% to 99.999% Al), used in electronics and CDs.

Heat sinks for electronic appliances such as transistors and CPUs.

Substrate material ofmetal-core copper clad laminates used in high brightness LED

lighting.

Powdered aluminium is used in paint, and inpyrotechnics such as solid rocket fuels

and thermite.

Aluminium can be reacted with hydrochloric acid to form hydrogen gas.

A variety of countries, including France, Italy, Poland,Finland, Romania, Israel, and

the formerYugoslavia, have issued coins struck in aluminium or aluminium-copper

alloys.[39]

Some guitar models sports aluminium diamond plates on the surface of the

instruments, usually either chrome or black. Kramer Guitars and Travis Bean are both

known for having produced guitars with necks made of aluminium, which gives the

instrument a very distinct sound.
http://en.wikipedia.org/wiki/Aluminium_canhttp://en.wikipedia.org/wiki/Windowhttp://en.wikipedia.org/wiki/Doorhttp://en.wikipedia.org/wiki/Sidinghttp://en.wikipedia.org/wiki/Cooking_utensilhttp://en.wikipedia.org/wiki/Baseball_bathttp://en.wikipedia.org/wiki/Mast_(sailing)http://en.wikipedia.org/wiki/Walking_polehttp://en.wikipedia.org/wiki/Walking_polehttp://en.wikipedia.org/wiki/Electrical_transmission_linehttp://en.wikipedia.org/wiki/MKM_steelhttp://en.wikipedia.org/wiki/Alnicohttp://en.wikipedia.org/wiki/Compact_dischttp://en.wikipedia.org/wiki/Heat_sinkhttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Central_processing_unithttp://en.wikipedia.org/w/index.php?title=Metal-core_copper_clad_laminates&action=edit&redlink=1http://en.wikipedia.org/wiki/LED_lightinghttp://en.wikipedia.org/wiki/LED_lightinghttp://en.wikipedia.org/wiki/Painthttp://en.wikipedia.org/wiki/Pyrotechnicshttp://en.wikipedia.org/wiki/Solid_rockethttp://en.wikipedia.org/wiki/Thermitehttp://en.wikipedia.org/wiki/Francehttp://en.wikipedia.org/wiki/Italyhttp://en.wikipedia.org/wiki/Polandhttp://en.wikipedia.org/wiki/Finlandhttp://en.wikipedia.org/wiki/Finlandhttp://en.wikipedia.org/wiki/Romaniahttp://en.wikipedia.org/wiki/Israelhttp://en.wikipedia.org/wiki/Yugoslaviahttp://en.wikipedia.org/wiki/Coinhttp://en.wikipedia.org/wiki/Aluminium#cite_note-38http://en.wikipedia.org/wiki/Kramer_Guitarshttp://en.wikipedia.org/wiki/Travis_Beanhttp://en.wikipedia.org/wiki/Aluminium_canhttp://en.wikipedia.org/wiki/Windowhttp://en.wikipedia.org/wiki/Doorhttp://en.wikipedia.org/wiki/Sidinghttp://en.wikipedia.org/wiki/Cooking_utensilhttp://en.wikipedia.org/wiki/Baseball_bathttp://en.wikipedia.org/wiki/Mast_(sailing)http://en.wikipedia.org/wiki/Walking_polehttp://en.wikipedia.org/wiki/Electrical_transmission_linehttp://en.wikipedia.org/wiki/MKM_steelhttp://en.wikipedia.org/wiki/Alnicohttp://en.wikipedia.org/wiki/Compact_dischttp://en.wikipedia.org/wiki/Heat_sinkhttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Central_processing_unithttp://en.wikipedia.org/w/index.php?title=Metal-core_copper_clad_laminates&action=edit&redlink=1http://en.wikipedia.org/wiki/LED_lightinghttp://en.wikipedia.org/wiki/LED_lightinghttp://en.wikipedia.org/wiki/Painthttp://en.wikipedia.org/wiki/Pyrotechnicshttp://en.wikipedia.org/wiki/Solid_rockethttp://en.wikipedia.org/wiki/Thermitehttp://en.wikipedia.org/wiki/Francehttp://en.wikipedia.org/wiki/Italyhttp://en.wikipedia.org/wiki/Polandhttp://en.wikipedia.org/wiki/Finlandhttp://en.wikipedia.org/wiki/Romaniahttp://en.wikipedia.org/wiki/Israelhttp://en.wikipedia.org/wiki/Yugoslaviahttp://en.wikipedia.org/wiki/Coinhttp://en.wikipedia.org/wiki/Aluminium#cite_note-38http://en.wikipedia.org/wiki/Kramer_Guitarshttp://en.wikipedia.org/wiki/Travis_Bean


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1.9.3. ALUMINIUM ALLOYS

Aluminium alloys are alloys in which aluminium (Al) is the predominant metal. The

typical alloying elements are copper, magnesium, manganese, silicon, and zinc. There are twoprincipal classifications, namely casting alloys and wrought alloys, both of which are further

subdivided into the categories heat-treatable and non-heat-treatable. 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

lowertensile strengths than wrought alloys. The most important cast aluminium alloy system

is Al-Si, where the high levels of silicon (4.0% to 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.

Alloys composed mostly of the two lightweight metals aluminium and magnesium

have been very important in aerospace manufacturing since somewhat before 1940.

Aluminium-magnesium alloys are both lighter than other aluminium alloys and much less

flammable than alloys that contain a very high percentage of magnesium.

Aluminium alloy surfaces will keep their apparent shine in a dry environment due to

the formation of a clear, protective layer ofaluminium oxide. In a wet environment, galvanic

corrosion can occur when an aluminium alloy is placed in electrical contact with other metals

with more negative corrosion potentials than aluminium.

Aluminium alloy compositions are registered with The Aluminum Association. Many

organizations publish more specific standards for the manufacture of aluminium alloy,

including the Society of Automotive Engineers standards organization, specifically its

aerospace standards subgroups, and ASTM International.
http://en.wikipedia.org/wiki/Alloyshttp://en.wikipedia.org/wiki/Aluminiumhttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Magnesiumhttp://en.wikipedia.org/wiki/Manganesehttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Zinchttp://en.wikipedia.org/wiki/Castinghttp://en.wikipedia.org/wiki/Heat_treatmenthttp://en.wikipedia.org/wiki/Extrudinghttp://en.wikipedia.org/wiki/Tensile_strengthhttp://en.wikipedia.org/wiki/Aerospace_manufacturinghttp://en.wikipedia.org/wiki/Aluminium_oxidehttp://en.wikipedia.org/wiki/Galvanic_corrosionhttp://en.wikipedia.org/wiki/Galvanic_corrosionhttp://en.wikipedia.org/wiki/The_Aluminum_Associationhttp://en.wikipedia.org/wiki/Society_of_Automotive_Engineershttp://en.wikipedia.org/wiki/ASTM_Internationalhttp://en.wikipedia.org/wiki/Alloyshttp://en.wikipedia.org/wiki/Aluminiumhttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Magnesiumhttp://en.wikipedia.org/wiki/Manganesehttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Zinchttp://en.wikipedia.org/wiki/Castinghttp://en.wikipedia.org/wiki/Heat_treatmenthttp://en.wikipedia.org/wiki/Extrudinghttp://en.wikipedia.org/wiki/Tensile_strengthhttp://en.wikipedia.org/wiki/Aerospace_manufacturinghttp://en.wikipedia.org/wiki/Aluminium_oxidehttp://en.wikipedia.org/wiki/Galvanic_corrosionhttp://en.wikipedia.org/wiki/Galvanic_corrosionhttp://en.wikipedia.org/wiki/The_Aluminum_Associationhttp://en.wikipedia.org/wiki/Society_of_Automotive_Engineershttp://en.wikipedia.org/wiki/ASTM_International


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1.9.3.1. ALUMINIUM ALLOYS IN STRUCTURAL APPLICATIONS

Aluminium alloys with a wide range of properties are used in engineering structures.

Alloy systems are classified by a number system (ANSI) or by names indicating their mainalloying constituents (DIN and ISO).

The strength and durability of aluminium alloys vary widely, not only as a result of the

components of the specific alloy, but also as a result of heat treatments and manufacturing

processes. A lack of the knowledge of these aspects has from time to time led to improperly

designed structures and gained aluminium a bad reputation. One important structural

limitation of aluminium alloys is their fatigue strength. Unlike steels, aluminium alloys have

no well-defined fatigue limit, meaning that fatigue failure eventually occurs, under even very

small cyclic loadings. This implies that engineers must assess these loads and design for a

fixed life rather than an infinite life.

Another important property of aluminium alloys is their sensitivity to heat. Workshop

procedures involving heating are complicated by the fact that aluminium, unlike steel, melts

without first glowing red. Forming operations where a blow torch is used therefore require

some expertise, since no visual signs reveal how close the material is to melting. Aluminium

alloys, like all structural alloys, also are subject to internal stresses following heating

operations such as welding and casting. The problem with aluminium alloys in this regard is

their low melting point, which make them more susceptible to distortions from thermally

induced stress relief. Controlled stress relief can be done during manufacturing by heat-

treating the parts in an oven, followed by gradual coolingin effect annealing the stresses.

The low melting point of aluminium alloys has not precluded their use in rocketry;

even for use in constructing combustion chambers where gases can reach 3500 K. The Agenaupper stage engine used a regeneratively cooled aluminium design for some parts of the

nozzle, including the thermally critical throat region.
http://en.wikipedia.org/wiki/American_National_Standards_Institutehttp://en.wikipedia.org/wiki/DINhttp://en.wikipedia.org/wiki/International_Organization_of_Standardizationhttp://en.wikipedia.org/wiki/Fatigue_(material)http://en.wikipedia.org/wiki/Fatigue_limithttp://en.wikipedia.org/wiki/Fatigue_(material)#Design_against_fatiguehttp://en.wikipedia.org/wiki/Blow_torchhttp://en.wikipedia.org/wiki/Melting_pointhttp://en.wikipedia.org/wiki/Annealing_(metallurgy)http://en.wikipedia.org/wiki/RM-81_Agenahttp://en.wikipedia.org/wiki/American_National_Standards_Institutehttp://en.wikipedia.org/wiki/DINhttp://en.wikipedia.org/wiki/International_Organization_of_Standardizationhttp://en.wikipedia.org/wiki/Fatigue_(material)http://en.wikipedia.org/wiki/Fatigue_limithttp://en.wikipedia.org/wiki/Fatigue_(material)#Design_against_fatiguehttp://en.wikipedia.org/wiki/Blow_torchhttp://en.wikipedia.org/wiki/Melting_pointhttp://en.wikipedia.org/wiki/Annealing_(metallurgy)http://en.wikipedia.org/wiki/RM-81_Agena


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1.9.3.2. ALUMINIUM 6063 ALLOY

Al 6063 is an aluminium alloy, with magnesium and silicon as the alloying elements.

The standard controlling its composition is maintained by The Aluminum Association. It hasgenerally good mechanical properties and is heat treatable and weld able. It is similar to the

British aluminium alloy HE9.

6063 Aluminium alloy is mostly used in extrudedshapes for architecture, particularly

window frames, door frames, and roofs. It is typically produced with very smooth surfaces fit

foranodizing.

1.9.3.3. CHEMICAL COMPOSITION OF ALUMINIUM 6063 ALLOY

Table1.1-Chemical Composition Of Aluminium 6063 AlloyCu Si Fe Mn Mg Zn Cr Ti Al

0.10 0.20 /

0.60

0.35 0.10 0.45 /

0.90

0.10 0.10 0.10 Balance

1.9.3.4. PHYSICAL PROPERTIES OF ALUMINIUM 6063 ALLOY

Table1.2-Physical Properties Of Aluminum 6063 Alloy

Property Value

Density 2.70g/cm3

Melting point 750o

CModulus of elasticity 69.5GPa

Electrical resistivity 0.35 x 10-6 ohm

Thermal conductivity 200 W/mK

Thermal expansion 23.5 x 10-6 /K

1.9.3.5. MECHANICAL PROPERTIES
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Table1.3- Mechanical Properties

Temper O T4 T6Minimum proof stress 0.2% (MPa) 50 60 160

Minimum tensile strength (MPa) 100 130 195Shear strength(MPa) 70 110 150

Elongation (%) 22 21 14

Hardness Vickers 25 50 80

1.10. IMPORTANT MECHANICAL PROPERTIES

a) TENSILE STRENGTH:-

It is the ability of the material to resist the externally applied forces without breaking or

yielding. Tensile strength measures the force required to pull something such as rope, wire, or

a structural beam to the point where it breaks. The tensile strength of a material is the

maximum amount oftensile stress that it can take before failure, for example breaking.

b) HARDNESS:-

Hardness is the measure of how resistant solidmatteris to various kinds of permanent

shape change when a force is applied. Macroscopic hardness is generally characterized bystrong intermolecular bonds, however the behavior of solid materials under force is complex,

therefore there are different measurements of hardness: scratch hardness, indentation

hardness, and rebound hardness. Hardness is dependent on ductility, elasticity, plasticity,

strain,strength, toughness, visco-elasticity, and viscosity. Common examples of hard matter

are ceramics, concrete, certainmetals, and super hard materials, which can be contrasted with

soft matter

c) BRITTLENESS:-

A material is brittle if, when subjected to stress, it breaks without significant

deformation (strain). Brittle materials absorb relatively little energy prior to fracture, even

those of highstrength. Breaking is often accompanied by a snapping sound. Brittle materials

include mostceramicsand glasses (which do not deform plastically) and somepolymers, such
http://simple.wikipedia.org/wiki/Forcehttp://simple.wikipedia.org/wiki/Ropehttp://simple.wikipedia.org/wiki/Wirehttp://simple.wikipedia.org/wiki/Materialhttp://simple.wikipedia.org/wiki/Materialhttp://simple.wikipedia.org/wiki/Tensile_stresshttp://simple.wikipedia.org/wiki/Tensile_stresshttp://en.wikipedia.org/wiki/Solidhttp://en.wikipedia.org/wiki/Solidhttp://en.wikipedia.org/wiki/Matterhttp://en.wikipedia.org/wiki/Matterhttp://en.wikipedia.org/wiki/Forcehttp://en.wikipedia.org/wiki/Forcehttp://en.wikipedia.org/wiki/Intermolecular_bondhttp://en.wikipedia.org/wiki/Ductilityhttp://en.wikipedia.org/wiki/Elasticity_(physics)http://en.wikipedia.org/wiki/Plasticity_(physics)http://en.wikipedia.org/wiki/Strain_(materials_science)http://en.wikipedia.org/wiki/Strength_of_materialshttp://en.wikipedia.org/wiki/Strength_of_materialshttp://en.wikipedia.org/wiki/Toughnesshttp://en.wikipedia.org/wiki/Toughnesshttp://en.wikipedia.org/wiki/Viscoelasticityhttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/wiki/Concretehttp://en.wikipedia.org/wiki/Metalshttp://en.wikipedia.org/wiki/Metalshttp://en.wikipedia.org/wiki/Superhard_materialshttp://en.wikipedia.org/wiki/Soft_matterhttp://en.wikipedia.org/wiki/Materialhttp://en.wikipedia.org/wiki/Stress_(physics)http://en.wikipedia.org/wiki/Strain_(materials_science)http://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Strength_of_materialshttp://en.wikipedia.org/wiki/Strength_of_materialshttp://en.wikipedia.org/wiki/Strength_of_materialshttp://en.wikipedia.org/wiki/Ceramicshttp://en.wikipedia.org/wiki/Ceramicshttp://en.wikipedia.org/wiki/Ceramicshttp://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Polymerhttp://en.wikipedia.org/wiki/Polymerhttp://simple.wikipedia.org/wiki/Forcehttp://simple.wikipedia.org/wiki/Ropehttp://simple.wikipedia.org/wiki/Wirehttp://simple.wikipedia.org/wiki/Materialhttp://simple.wikipedia.org/wiki/Tensile_stresshttp://en.wikipedia.org/wiki/Solidhttp://en.wikipedia.org/wiki/Matterhttp://en.wikipedia.org/wiki/Forcehttp://en.wikipedia.org/wiki/Intermolecular_bondhttp://en.wikipedia.org/wiki/Ductilityhttp://en.wikipedia.org/wiki/Elasticity_(physics)http://en.wikipedia.org/wiki/Plasticity_(physics)http://en.wikipedia.org/wiki/Strain_(materials_science)http://en.wikipedia.org/wiki/Strength_of_materialshttp://en.wikipedia.org/wiki/Toughnesshttp://en.wikipedia.org/wiki/Viscoelasticityhttp://en.wikipedia.org/wiki/Ceramichttp://en.wikipedia.org/wiki/Concretehttp://en.wikipedia.org/wiki/Metalshttp://en.wikipedia.org/wiki/Superhard_materialshttp://en.wikipedia.org/wiki/Soft_matterhttp://en.wikipedia.org/wiki/Materialhttp://en.wikipedia.org/wiki/Stress_(physics)http://en.wikipedia.org/wiki/Strain_(materials_science)http://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Strength_of_materialshttp://en.wikipedia.org/wiki/Ceramicshttp://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Polymer


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2.1. LITERATURE REVIEW

Heat treatment processes for aluminium are precision processes. Based on the

objectives of this research, precipitate free zones in the aluminium alloy 6063 actually give

bad effect to the mechanical properties of that alloy. The mechanical properties of the

aluminium alloy should be altering properly to improve their behavior using precipitation

hardening which one of the heat treatment types. Precipitation hardening is the most suitable

heat treatment that should use to minimize the precipitate free zones in the microstructure of

the aluminium alloy 6063. In the precipitation hardening process, the thermal and temperature

condition is under control with high precision to ensure the transformation of the aluminium

alloy structure is in good condition and supervision limit. The samples of the material areplaced in the furnace to make a heat treating process and then quench it in the water for

quenching medium. The material testing that had been applied is based on hardness, impact

and microstructure analysis. The purpose of the hardness testing are to find out the hardness

reading for all the samples that used to look the wear resistance effect that occur after make a

heat treating process to the aluminium alloy 6063. From the impact test, the purposes are to

know impact 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 narrow evaluation of precipitate free zones in

the microstructure of aluminium alloy after make a precipitation hardening processes. From

the data and result that already determined, it shown the positive result based on objectives

and scope of this project.


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The literature review of existing heat treatments indicates that heat straightening with

maximum temperature limited to 1200F is relatively similar to the process annealing heat

treatment. Heat straightening with maximum temperature limited to 1400oF is similar to the

normalizing annealing heat treatment. Both these heat treatments repair plastically deformed

microstructure by the phenomenon known as recovery and recrystallization. Normalizing

annealing is more efficient and faster than process annealing in repairing the plastically

deformed microstructure by recrystallization. Heat treatment and repair of the material

microstructure is incidental to the heat straightening repair process. The heat straightened

beam can be further heat treated to complete the repair of the material microstructure

(recrystallization etc.). The practical and economic feasibility of additional heat treatment

using electrically powered and controlled radiant heaters was evaluated and found to bereasonable.

The effects of heat treatment on the dynamic compressive properties and energy

absorption characteristics of open cell aluminium 6063 alloy produced by

infiltrating process were studied. various kinds of heat treatment were exploited such as

quenching normalising and annealing. Tensile compressive and hardness test has been

performed to define the properties of aluminium 6063 alloy. The results show that tha

hardness of the alloy increases also it softens on quenching the grain structure also define bythe tests .

The effects of solution-ageing treatment on the mechanical properties of aluminium

6063 products were studied by the method of orthogonal experiment. The mechanical

properties at different treatment conditions were analyzed. The results show that the effects of

heat treatment were obviously influenced by the original microstructure of the aluminium

60603. Higher temperature is favorable for the sufficient solution of alloy elements, but the

grains will grow up when treated at a higher temperature or soaked for a longer time. There is

a contradiction between the maximum tensile strength and elongation percentage. The surplus

phases not melted in the substrate and the solution precipitated supersaturated elements are

the main factors influencing the properties of the alloys.


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To examine the effectiveness of the treatment, simulating experiments are conducted

using a heat-treatable 6063 aluminum alloy, and the grain size, hardness property, and tensile

properties are measured and compared with those of the conventionally heat-treated sheets.

The results are summarized as follows: (1) resistance heating at a current density of about

100 A mm2 realizes heating the aluminum alloy sheet into the solution temperature range in

2 s, (2) complete achievement of rapid solution treatment by the resistance heating requires

the condition that the precipitates exist finely in the matrix, (3) the new treatment decreases

the grain size by approximately one-half but the mechanical properties are not remarkably

improved.

A systematic experimental investigation of the effect of heat-treatment technique on

the mechanical properties of 6063 aluminum alloy was carried out. Particularly, an artificial

neural network and a genetic algorithm were used to search for the optimum technique,

adapted for 6063 aluminum alloy. The results indicated strongly that an artificial neural

network combined with a genetic algorithm indeed offer a new effective means for the

optimization of materials processing technique.

A series of heat treatments were made on samples cut from bars of a 6063

heat treatable aluminum alloy that were solubilized for 4 h at 520 C, and were cooled down

to room temperature by placing one of their ends into a shallow tank of water to produce a

continuous thermal gradient along their length. Heating and cooling are carried

simultaneously for carrying out different tests. Various test are being conducted on different

equipments such as UTM machine is being used for testing compressive and tensile tests of

aluminium 6063 alloy . for hardness test Rockwell hardness test is being conducted IZOD

and Charpy tests are being conducted to find the impact strength of aluminium 6063 alloy.

These tests are performed on different temperatures for carrying out Quenching, Normalising

and Annealing processes and results are being calculated.


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CHAPTER - 3

METHODOLOGY AND TESTS

PERFORMED


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c) HARDENING: - Hardening is performed at 525oC for 3 hrs and then immediately

quenched in water.

This is applicable to the heat treatable alloys and involves a heat treatment process

whereby the alloying constituents are taken into solution and retained by rapid quenching.

Subsequent heat treatment at tower temperatures i.e. ageing or natural ageing at room

temperature allows for a controlled precipitation of the constituents thereby achieving

increased hardness and strength. Time at temperature for solution treatment depends on

the type of alloy and the furnace load. Sufficient time must be allowed to take the alloys

into solution if optimum properties are to be obtained.

5) Now we will again measure all the mechanical properties which we had checked

earlier.

6) Now compare the properties of aluminium 6063 alloy before & after heat treatment

3.2. TESTS PERFORMED ON ALUMINUM 6063 ALLOY

3.2.1. TENSILE TEST

Tensile testing, also known as tension testing, is a fundamental materials science test

in which a sample is subjected to uniaxial tension until failure. The results from the test are

commonly used to select a material for an application, forquality 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 and reduction in area. From

these measurements the following properties can also be determined: Young's modulus,

Poisson's ratio, yield strength, and strain-hardening characteristics.

3.2.1.1. Tensile Test Specimen
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A tensile test specimen is a standardized sample cross-section. It has two shoulders

and a gage section in between. The shoulders are large so they can be readily gripped, where

as the gage section has a smaller cross-section so that the deformation and failure can occur in

this area.

The shoulders of the test specimen can be manufactured in various ways to mate to various

grips in the testing machine (see the image below). Each system has advantages and

disadvantages; for example, shoulders designed for serrated grips are easy and cheap to

manufacture, but the alignment of the specimen is dependent on the skill of the technician. On

the other hand, a pinned grip assures good alignment. Threaded shoulders and grips also

assure good alignment, but the technician must know to thread each shoulder into the grip at

least one diameter's length, otherwise the threads can strip before the specimen fractures.

In large castings and forgings it is common to add extra material, which is designed to be

removed from the casting so that test specimens can be made from it. These specimen not be

exact representation of the whole work piece because the grain structure may be different

throughout. In smaller work pieces or when critical parts of the casting must be tested, a work

piece may be sacrificed to make the test specimens. For work pieces that are machined from

bar stock, the test specimen can be made from the same piece as the bar stock.

3.2.2. IZOD IMPACT TEST:-

Izod impact strength testing is an ASTM standard method of determining impact

strength. A notched sample is generally used to determine impact strength.

The test is named after the English engineer Edwin Gilbert Izod (18761946), who

described it in his 1903 address to the British Association, subsequently published in

Engineering.

The specimen is clamped into the pendulum impact test fixture with the notched side

facing the striking edge of the pendulum. The pendulum is released and allowed to strike

through the specimen. If breakage does not occur, a heavier hammer is used until failure
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occurs. Since many materials (especially thermoplastics) exhibit lower impact strength at

reduced temperatures, it is sometimes appropriate to test materials at temperatures that

simulate the intended end use environment.

Impact is a very important phenomenon in governing the life of a structure. In the case

of aircraft, impact can take place by the bird hitting the plane while it is cruising, during take

off and landing there is impact by the debris present on the runway

An arm held at a specific height (constant potential energy) is released. The arm hits

the sample and breaks it. From the energy absorbed by the sample, its impact strength is

determined.

The dimensions of a standard specimen for ASTM D256 are 4 x 12.7 x 3.2 mm (2.5" x

0.5" x 1/8"). The most common specimen thickness is 3.2 mm (0.125"), but the width can

vary between 3.0 and 12.7 mm (0.118" and 0.500").

This test can also be used to determine the notch sensitivity.

3.2.3CHARPY IMPACT TEST:-The Charpy impact test, also known as the Charpy v-notch test, is a standardized high

strain-rate test which determines the amount ofenergy absorbed by a material during fracture.

This absorbed energy is a measure of a given material's toughness and acts as a tool to study

temperature-dependent brittle-ductile transition. It is widely applied in industry, since it is

easy to prepare and conduct and results can be obtained quickly and cheaply. But a major

disadvantage is that all results are only comparative.

The test was developed in 1905 by the French scientist Georges Charpy. It was pivotal

in understanding the fracture problems of ships during the Second World War. Today it is

used in many industries for testing building and construction materials used in the

construction of pressure vessels, bridges and to see how storms will affect materials used in

building.
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The apparatus consists of a pendulumaxe swinging at a notched sample of material.

The energy transferred to the material can be inferred by comparing the difference in the

height of the hammer before and after a big fracture.

The notch in the sample affects the results of the impact test, thus it is necessary for

the notch to be of regular dimensions and geometry. The size of the sample can also affect

results, since the dimensions determine whether or not the material is in plane strain. This

difference can greatly affect conclusions made.

The "Standard methods for Notched Bar Impact Testing of Metallic Materials" can be

found in ASTM E23, ISO 148-1 or EN 10045-1, where all the aspects of the test and

equipment used are described in detail.

3.2.4. ROCKWELL HARDNESS TEST

The Rockwell scale is a hardness scale based on the indentation hardness of a material.

The Rockwell test determines the hardness by measuring the depth of penetration of an

indenter under a large load compared to the penetration made by a preload. There are different

scales, which are denoted by a single letter, that use different loads or indenters. The result,

which is a dimensionless number, is noted by HRX where X is the scale letter.

When testing metals, indentation hardness correlates linearly with tensile strength.

This important relation permits economically important nondestructive testing of bulk metal

deliveries with lightweight, even portable equipment, such as hand-held Rockwell hardness

testers
http://en.wikipedia.org/wiki/Pendulumhttp://en.wikipedia.org/wiki/Axehttp://en.wikipedia.org/wiki/Inferhttp://en.wikipedia.org/wiki/Hardnesshttp://en.wikipedia.org/wiki/Indentation_hardnesshttp://en.wikipedia.org/wiki/Tensile_strengthhttp://en.wikipedia.org/wiki/Pendulumhttp://en.wikipedia.org/wiki/Axehttp://en.wikipedia.org/wiki/Inferhttp://en.wikipedia.org/wiki/Hardnesshttp://en.wikipedia.org/wiki/Indentation_hardnesshttp://en.wikipedia.org/wiki/Tensile_strength


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CHAPTER - 4

RESULTS AND ANALYSIS

4.1. TESTS PERFORMED

4.1.1. TENSILE TEST

BEFORE HEAT TREATMENT:-

a- Original dimensions:

Diameter of specimen (d1) = 10mm

Cross sectional area of specimen (A1)= 1)2 mm2 = 78.53mm2


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Gauge length of specimen (l1) = 5.65 1 = 50.0 mm

b- Final dimensions:

Diameter of specimen (d2) = mm

Cross sectional area of specimen (A2)= 2)2 mm2

Gauge length of specimen (l2) = 5.65 2

Table No.4.1- Tensile Test Table Before Heat Treatment

S.No Ultimate

load

(kN)

Extension

(l2-l1) mm

Ultimate

strength=

(MPa)

% elongation = % reduction in

area =

1 18.5 60-50=10 235.5 20 84.00

2 16.25 58-50=8 206.9 16 80.66

3 18.0 59-50=9 229.1 18 82.36

Mean diameter at breaking point = 4.2mm

1- Mean Ultimate strength = (235.5+206.6+229.1) / 3

= 223.8 MPa

2- Mean % elongation = (20+16+18) / 3

= 18 %


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3- Mean % reduction in area = (84+80.66+82.36) / 3

= 82.34 %

FFig 4.1 Tensile Test Specimen Before Heat Treatment

AFTER HEAT TREATMENT:-

i) TENSILE TEST AFTER NORMALIZING:-

Table No.4.2- Tensile Test Table After Normalizing

S.No Ultimate

load

(kN)

Extension

(l2-l1) mm

Ultimate

strength=

(MPa)


area =

1 8.5 64-50=14 108.2 28 82.36

2 9 63-50=13 114.6 26 81.5

3 9.2 64-50=14 117.15 28 82.36

Area =/4(D12)


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= /4(10)2 = 78.53 mm2

Ultimate strength = 1000

(i) Ultimate strength= (8.5 x1000) / 78.53 = 108.2 MPa

(i) Ultimate strength= (9 x1000) / 78.53 = 114.6 MPa

(iii) Ultimate strength= (9.2 x1000) / 78.53 = 117.15 MPa

Mean ultimate strength = (108.2+114.6+117.15) / 3 = 113.31 MPa

Percentage elongation =

(i) % age elongation = [(64-50) / 50] x100 = 28%

(ii) % age elongation = 26%

(iii)% age elongation = 28%Mean percentage elongation = (28+26+28) / 3 = 27.33 %

Percentage reduction in area =

A1=78.53 mm2

(i) A2= /4 x (4.2)2 = 13.85 mm2

%age reduction= 82.36%

(ii) A2= /4 x (4.3)2 = 14.52 mm2



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(iii) A2= /4 x (4.2)2 = 13.85 mm2


Mean reduction in area = (82.36+81.5+82.36) / 3= 82.07%

ii) TENSILE TEST AFTER QUENCHING:-

Table No.4.3- Tensile Test Table After Quenching

S.No Ultimate

load(kN)

Extension

(l2-l1) mm

Ultimate

strength=

(MPa)


area =

1 9.75 60-50=10 124.15 20 76.9

2 10 63-50=13 127.15 26 84.00

3 9.5 61-50=11 120.97 22 19.63

Area =/4(D12)

= /4(10)2 = 78.5mm2


(i) Ultimate strength= (9.75 x1000) / 78.53 = 124.15 MPa

(ii) Ultimate strength= (10 x1000) / 78.53 = 127.33 MPa

(iii) Ultimate strength= (9.5 x1000) / 78.53 = 120.97 MPa

Mean ultimate strength = (12.15 + 127.33 + 120.97) / 3 = 124.15 MPa


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(i) % age elongation = [(60-50) / 50]x100 = 20%

(ii) % age elongation = [(63-50) / 50]x100 = 26%

(iii) % age elongation = [(61-50) / 50]x100 = 22%

Mean percentage elongation = (20+26+22) / 3 = 22.66 %


A1=78.53 mm2

(i) A2= /4 x (4.8)2 = 18.095 mm2

%age reduction= [(78.53-18.0955) / 78.53] x100

= 76.9%

(ii) A2= /4 x (4)2 = 12.56 mm2


(iii) A2= /4 x (5)2 = 19.6325 mm2


Mean reduction in area = (76.9+ 84+ 75) / 3= 78.63%

iii) TENSILE TEST AFTER ANNEALING:-

Table No.4.4- Tensile Test Table After Annealing


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S.No Ultimate

load

(kN)

Extension

(l2-l1) mm

Ultimate

strength=

(MPa)


area =

1 6 68-50=18 76.403 36 87.7

2 6 66-50=16 78.95 32 85.5

3 6 68-50=18 77.25 36 87.7

Area =/4(D12)

= /4(10)2

= x 25= 78.5 mm2


(i) Ultimate strength= (6 x1000) / 78.53 = 76.403 MPa

(ii) Ultimate strength= (6 x1000) / 78.53 = 78.95 MPa

(iii) Ultimate strength= (6 x1000) / 78.53 = 76.403 MPa

Mean ultimate strength = (76.403+78.95+76.403) / 3 = 77.25 MPa


(i) % age elongation = [(68-50) / 50]x100 = 36%

(ii) % age elongation = 32%

(iii) % age elongation = 36%

Mean percentage elongation = (36+32+36) / 3 = 34.66 %


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A1=78.53 mm2

(i) A2= /4 x (3.5)2 = 9.6 mm2


(ii) A2= /4 x (3.8)2 = 11.34 mm2


(iii) A2= /4 x (3.5)2 = 9.6 mm2


Mean reduction in area = (87.7+85.5

“to study the effect of heat treatment processes on the properties of aluminum 6063 alloy’’

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