Tribological and Mechanical Behaviour of Hybrid Metal Matrix Composite

8/19/2019 Tribological and Mechanical Behaviour of Hybrid Metal Matrix Composite

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TRIBOLOGICAL AND MECHANICAL BEHAVIOUR OF

HYBRID METAL MATRIX COMPOSITE

CHAPTER 1

INTRODUCTION

Composite materials (also called composition materials or shortened to

composites) are materials made from two or more constituent materials with

significantly different physical or chemical properties, that when combined,

produce a material with characteristics different from the individual components.

The individual components remain separate and distinct within the finished

structure. A typical composite material is a system of materials composing of two

or more materials (mixed and bonded) on a macroscopic scale. For example,

concrete is made up of cement, sand, stones, and water. f the composition occurs

on a microscopic scale (molecular level), the new material is then called an alloy

for metals or a polymer for plastics.

!enerally, a composite material is composed of reinforcement (fibers,

particles, fla"es and fillers) embedded in a matrix (polymers, metals or ceramics).

The matrix holds the reinforcement to form the desired shape while the

reinforcement improves the overall mechanical properties of the matrix. #hen

designed properly, the new combined material exhibits better strength than would

each individual material.

n general, fibers are the principle load carrying members, while the

surrounding matrix "eeps them in the desired location and orientation, acts as a

load transfer medium between them and protects them from environmental

damages due to elevated temperature and humidity.

$roperties of composites are strongly influenced by the properties of their

constituent materials, their type, their distribution and the interaction between

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them. %i"e conventional materials, composites are not homogeneous and isotropic.

Composites are generally completely elastic up to failure exhibit no yield point or a

region of plasticity. Composites that forms heterogeneous structures which meet

the re&uirements of specific design and function, imbued with desired properties

which limit the scope for classification. 'owever, this lapse is made up for, by the

fact new types of composites are being innovated all the time, each with their own

specific purpose li"e the filled, fla"e, particulate and laminar composites. n

matrixbased structural composites, the matrix serves two paramount purposes vi.,

binding the reinforcement phases in place and deforming to distribute the stresses

among the constituent reinforcement materials under an applied force.

1.1 COMMON CATEGORIES OF COMPOSITE MATERIALS

*ased on the form of reinforcement, common composite materials can be

classified as follows+

Figure 1.1 Ran!" #i$er %&'!r( #i$er) rein#!r*e *!"+!&i(e&

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Figure 1., Par(i*u-a(e *!"+!&i(e

Figure 1. F-a/e *!"+!&i(e&

Figure 1.0 Fi--er *!"+!&i(e&

1., BENEFITS OF COMPOSITES

#hen composites are selected over traditional materials such as metal alloys

or woods, it is usually because of one or more of the following+

1.,.1 C!&(

$rototypes

-ass production

$art consolidation

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-aintenance

%ong term durability

$roduction time

-aturity of technology

1.,., eig'(

%ight weight

#eight distribution

1.,. S(reng(' an &(i##ne&&

'igh strengthtoweight ratio

irectional strength and/or stiffness

1.,.0 Di"en&i!n

%arge parts

0pecial geometry

1.,.2 Sur#a*e +r!+er(ie& Corrosion resistance

#eather resistance

Tailored surface finish

1.,.3 T'er"a- +r!+er(ie&

%ow thermal conductivity

%ow coefficient of thermal expansion

1.,.4 E-e*(ri* +r!+er(5

'igh dielectric strength

1onmagnetic

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2adar transparency.

1. CLASSFICATION OF COMPOSITE MATERIALS

The composite materials are classified as follows

3. -etal matrix composites

4. $olymer matrix composites

5. Ceramic matrix composites

1..1 Me(a- "a(ri6

-etal matrix composites, at present though generating a wide interest in

research fraternity, are not as widely in use as their plastic counterparts. 'igh

strength, fracture toughness and stiffness are offered by metal matrices than thoseoffered by their polymer counterparts. They can withstand elevated temperature in

corrosive environment than polymer composites. -ost metals and alloys could be

used as matrices and they re&uire reinforcement materials which need to be stable

over a range of temperature and nonreactive too. 'owever the guiding aspect for

the choice depends essentially on the on the matrix material. %ight metals form the

matrix for temperature application and the reinforcements in addition to the

aforementioned reasons are characteried by high modulus

-ost metals and alloys ma"e good matrices. 'owever, practically, the

choices for low temperature applications are not many. 6nly light metals are

responsive, with their low density proving an advantage. Titanium, Aluminium and

magnesium are the popular matrix metals currently in vogue, which are

particularly useful for aircraft applications. f metallic matrix materials have to

offer high strength, they re&uire high modulus reinforcements.

The strengthtoweight ratios of resulting composites can be higher than

most alloys. The melting point, physical and mechanical properties of the

composite at various temperatures determine the service temperature of

composites.

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-ost metals, ceramics and compounds can be used with matrices of low

melting point alloys. The choice of reinforcements becomes more stunted with

increase in the melting temperature of matrix materials.

The development ob7ectives for light metal composite material are,

ncrease in yield strength and tensile strength at room temperature and above

while maintaining the minimum ductility or rather toughness.

ncrease in creep resistance at higher temperature compared to that of

Conventional alloys.

ncrease in fatigue strength, especially at higher temperature.

mprovement of thermal shoc" resistance.

ncrease in young8s modulus.

2eduction of thermal elongation.

2einforcement of metal matrix composite have a manifold demand profile

which is determined by production and processing and by the matrix system of the

composite material ,the following demands are generally applicable +

%ow density

-echanical compatibility

Chemical compatibility

Thermal stability

'igh young8s modulus.

!ood process ability

9conomic efficiency

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CHAPTER ,

LITERATURE REVIE

7.7. C'a8-a e( a-.9 :1;. -etalmatrix composites (--Cs) are engineered

combinations of two or more materials (one of which is a metal) where tailored

properties are achieved by systematic combinations of different constituents.

Conventional monolithic materials have limitations in respect to achievable

combinations of strength, stiffness and density. 9ngineered --Cs consisting of

continuous or discontinuous fibres, whis"ers, or particles in a metal achieve

combinations of very high specific strength and specific modulus. Furthermore,systematic design and synthesis procedures allow uni&ue combinations of

engineering properties in composites li"e high elevated temperature strength,

fatigue strength, damping property, electrical and thermal conductivities, friction

coefficient, wear resistance and expansion coefficient.

T.. C-5ne an P.


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I.A. I$ra'i" e( a-.9:0;. The modem composites are non e&uilibrium

combinations of metals and ceramics, where there are fewer thermodynamic

restrictions on the relative volume percentages, shapes and sie of ceramic phases.

S. Ra5 :2;. Composite materials are attractive since they offer the possibility

of attaining property combinations which are not obtained in monolithic materials

and which can result in a number of significant service benefits. These could

include increased strength, decreased weight, higher service temperature, improved

wear resistance, higher elastic modulus, controlled coefficients of thermal

expansion and improved fatigue properties.

S.V. Pra&a an R. A&('ana e( a-.9 :3;.The &uest for improved performance

has resulted in a number of developments in the area of --C fabrication

technology .These includes both the preparation of the reinforcing phases and the

development of fabrication techni&ues. A number of composite fabrication

techni&ues have been developed that can be placed into four broad categories.

These are powder metallurgical techni&ues, li&uid metallurgy. The li&uid

metallurgy techni&ues include unidirectional solidifications to produce

directionally aligned --Cs, suspension of reinforcement in melts followed by

solidification, compo casting, s&ueee casting, spray casting, and pressure

infiltration. The li&uid metallurgy techni&ues are the least expensive of all, and the

multistep diffusion bonding techni&ues may be the most expensive.

B.P. 7ri&'nan e( a-.9 :4;.!raphite is a soft grayishblac" greasy substance.

The word graphite comes from a !ree" word meaning :to write8. The lead in our

writing pencils is graphite mixed with clay. !raphite is also "nown as blac" lead or

plumb ago. !raphite is also crystallied carbon. The carbon atoms of graphite form

a crystal pattern that differs from that of the carbon atoms in diamond. n graphite,

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the carbon atoms are arranged in flat planes of hexagonal rings stac"ed on one

another. This free electron accounts for the electrical conductivity of graphite. The

lac" of carboncarbon bonding between ad7acent planes enables them to slide over

each other ma"ing graphite soft, slippery and useful as a lubricant. The presence of

free electrons ma"es graphite a good conductor of electricity and it is used to ma"e

electrodes.

S. Bi&8a& e( a-.9:=;.!raphite has the following properties. (i) !raphite is a

soft, slippery, grayishblac" substance. t has a metallic luster and is opa&ue to

light. (ii)0pecific gravity of graphite is 4.5. (iii)!raphite is a good conductor of

heat and electricity. (iv)Although graphite is a very stable allotrope of carbon but at

a very high temperature it can be transformed into artificial diamond.

(v)Chemically, graphite is slightly more reactive than diamond.

S.Ven/a(e&' e( a-.9:>;. 0ubse&uently several aluminum companies further

refined and modified the process which is currently employed to manufacture a

variety of aluminum metal matrix composites on commercial scale and also which

is used to manufacturing the automobile parts.

7.Sara?ana/u"ar e( a-.9 :1@;. many optimiation techni&ues and design of

experiment techni&ues are used to find the best combinations composite

parameters by this techni&ue the &uality of metal matrix composites are increased.

n this wor" taguchi techni&ue through %; orthogonal array is used to find the best

combinations of metal matrix composites.

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CHAPTER

PROBLEM IDENTIFICATION

From the literature survey we have identified the problem that nic"el and

cobalt has less oxidation resistance. 0o, this material is not used in aerospace.

9arlier composites ma"e corrode li"e metals, the combination of corrosion

and fatigue crac"ing is a significant problem for aluminum commercial fuselage

structure. -agnesium has less atmospheric corrosion resistance. 1ic"el, Cobalt,

-agnesium and *oron and others are cost wise high. Cost of a material is a big problem.


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CHAPTER 0

METHODOLOGY

0election of matrix and reinforcement

(AA =>=3 ? Fly ash ? !raphite)

To prepare the various specimens using

0tir casting route

-easuring dimensions and $reparation of

ndividual specimens

Testing on -echanical and Tribological properties

of the various specimens

Conducting -icrostructural analysis for the

@arious specimens

To obtain the results and conclusions

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CHAPTER 2

MATERIALS AND METHODSS

2.1 MATRIX

The matrix is the monolithic material into which the reinforcement is

eembedded, and is completely continuous. This means that there is a path through

the matrix to any point in the material, unli"e two materials sandwiched together.

n a composite material, the matrix material serves the following functions+

3. 'olds the fibers together.

4. $rotects the fibers from environment.

5. 9nhances transverse properties of a laminate.

. mproves impact and fracture resistance of a component.

B. 'elps to avoid propagation of crac" growth through the fibers by

providing alternate failure path along the interface between the fibers

and the matrix.

=. Carry inner laminar shear.

2., MATRIX MATERIAL

2.,.1 A-u"iniu"

Aluminium is the matrix and reinforcement is usually nonmetallic and

ceramic materials. $roperties of A-Cs can be tailored by varying the nature of

constituents and their volume fraction. The ma7or advantage of A-Cs compared to

unreinforcement materials are as follows.

!reater strength

mproved stiffness

2educed density

mproved high temperature properties

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Controlled thermal expansion coefficient

Thermal/ heat management

9nhanced and tailored electrical performance.

mproved abrasion and wear resistance.

mproved damping properties

2.,., Pr!+er(ie& !# A-u"iniu" 3@31

Typical properties of aluminium alloy =>=3 include+

-edium to high strength

!ood toughness

!ood surface finish

9xcellent corrosion resistance to atmospheric conditions

!ood corrosion resistance to sea water

Can be anodied

!ood weldability and braability

!ood wor"ability

#idely available

Ta$-e 2.1 C'e"i*a- C!"+!&i(i!n !# A-u"iniu" A--!5

E-e"en( eig'(

Al ;.

Cu >.3B

-g >.

Dn >.4B

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2.,. A++-i*a(i!n&

Typical applications for aluminium alloy =>=3 include+

Aircraft and aerospace components

-arine fittings

Transport

*icycle frames

Camera lenses

rive shafts

9lectrical fittings and connectors

*ra"e components

@alves

Couplings2. REINFORCEMENT

The reinforcement material is embedded into the matrix the reinforcement does

not always serve a purely structural tas" (reinforcing the compound), but is also

used to change physical properties such as wear resistance, friction coefficient, or

thermal conductivity. 2einforcement materials are,

• Fly ash and !raphite

2.0 FLY ASH

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Fly ash is one of the residues generated in combustion, and comprises the

fine particles that rise with the flue gases. Ash which does not rise is termed

bottom ash. Fly ash is generally captured by electrostatic precipitators or other

particle filtration e&uipments before the flue gases reach the chimneys of coalfired

power plants, and together with bottom ash removed from the bottom of the

furnace is in this case 7ointly "nown as coal ash.

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 &uantities (>million tons per year) at very low costs since much of this

is currently land filled. The high electrical resistivity, low thermal conductivity and

low density of flyash may be helpful for ma"ing a light weight insulating

composites.

Ta$-e 2., C'e"i*a- C!"+!&i(i!n !# F-5 A&'

Component *ituminous 0ub bituminous %ignite

0i64 (E) 4>=> >=> 3BB

Al465 (E) B5B 4>5> 4>4BFe465 (E) 3>> 3> 3B

Ca6 (E) 334 B5> 3B>

Fly ash as a filler in Al casting reduces cost, decreases density and increase

hardness, stiffness, wear and abrasion resistance. t also improves the

machinability, damping capacity, coefficient of friction etc. which are needed in

various industries li"e automotive etc. n the fly ash increases hardness alsoincreases. Toxic constituents depend upon the specific coal bed ma"eup, but may

include one or more of the following elements or substances in &uantities from

trace amounts to several percent+ arsenic, beryllium, boron, cadmium, chromium,

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chromium @, cobalt, lead, manganese, mercury, molybdenum, selenium,

strontium, thallium, and vanadium, along with dioxins and $A' compounds.

Fly ash material solidifies while suspended in the exhaust gases and is

collected by electrostatic precipitators or filter bags.

Figure 2.1 F-5 a&' P!8er

0ince the particles solidify rapidly while suspended in the exhaust gases,

flyash particles are generally spherical in shape and range in sie from >.B m

to5>> m.

2.0.1 C-a&& F #-5 a&'

The burning of harder, older anthracite and bituminous coal typically

produces Class F fly ash. This fly ash is poolanic in nature, and contains less

than 4>E lime (Ca6). $ossessing poolanic properties, the glassy silica and

alumina of Class F fly ash re&uires a cementing agent, such as $ortland cement,

&uic"lime, or hydrated lime, with the presence of water in order to react and

produce cementitious compounds.

2.0., C-a&& C #-5 a&'

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Fly ash produced from the burning of younger lignite or subbituminous coal,

in addition to having poolanic properties, also has some selfcementing

properties. n the presence of water, Class C fly ash will harden and gain strength

over time. Class C fly ash generally contains more than 4>E lime (Ca6).


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mechanical treatment and the beta form reverts to the alpha form when it is heated

above 35>> IC.

Figure 2., S*anning (unne-ing "i*r!&*!+e i"age !# gra+'i(e &ur#a*e a(!"&

Figure 2. Gra+'i(e& uni( *e--

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Figure 2.0 Ani"a(e ?ie8 !# ('e uni( *e-- in ('ree -a5er& !#

gra+'ene

Figure 2.2 Ba--an&(i*/ "!e- !# gra+'i(e %(8! gra+'ene -a5er&)

Figure 2.3 Sie ?ie8 !# -a5er &(a*/ing

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Figure 2.4 P-ane ?ie8 !# -a5er &(a*/ing

2.2., Pr!+er(ie&

The acoustic and thermal properties of graphite are highly anisotropic,

since phonons propagate &uic"ly along the tightlybound planes, but are slower to

travel from one plane to another.!raphite can conduct electricity due to the

vast electron delocaliation within the carbon layers (a phenomenon

called aromaticity). These valence electrons are free to move, so are able to

conduct electricity. 'owever, the electricity is primarily conducted within the planeof the layers. The conductive properties of powdered graphite allowed its use as a

semiconductor substitute in early carbon microphones.

!raphite and graphite powder are valued in industrial applications for their

selflubricating and dry lubricating properties. There is a common belief that

graphiteJs lubricating properties are solely due to the loose interlamellar

coupling between sheets in the structure. 'owever, it has been shown that in

a vacuum environment (such as in technologies for use in space), graphite is a

verypoor lubricant. This observation led to the hypothesis that the lubrication is

due to the presence of fluids between the layers, such as air and water, which are

naturally adsorbed from the environment. This hypothesis has been refuted by

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studies showing that air and water are not absorbed. 2ecent studies suggest that an

effect called superlubricity can also account for graphiteJs lubricating properties.

The use of graphite is limited by its tendency to facilitate pitting corrosion in

some stainless steel, and to promote galvanic corrosion between dissimilar metals

(due to its electrical conductivity). t is also corrosive to aluminium in the presence

of moisture. For this reason, the >>K35>> IC then it is

isotropic turbostratic, and is used in blood contacting devices li"e mechanical heart

valves and is called (pyrolytic carbon), and is not diamagnetic. $yrolytic graphite,

and pyrolytic carbon are often confused but are very different materials.

1atural and crystalline graphites are not often used in pure form as structural

materials, due to their shearplanes, brittleness and inconsistent mechanical

properties.

Ta$-e 2. Pr!+er(ie& !# Gra+'i(e

0.16 $26$92TL C6--92CA% !2A$'T9

3 *ul" ensity (g/cm5) 3.53.;B

4 $orosity (E) >.GB5

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5 -odulus of 9lasticity (!$a) 3B

Compressive strength (-$a) 4>4>>

B Coefficient of Thermal 9xpansion(3>= IC) 3.4.4

= Thermal conductivity (#/m.M) 4BG>

G 9lectrical resistivity (N.m) Bx3>=5>x3>=

2.2. U&e& !# Gra+'i(e

1atural graphite is mostly consumed for refractories, batteries, steelma"ing,

expanded graphite, bra"e linings, foundry facings and lubricants.!raphene, whichoccurs naturally in graphite, has uni&ue physical properties and might be one of the

strongest substances "nownO however, the process of separating it from graphite

will re&uire some technological development before it is economically feasible to

use it in industrial processes.

3.Amorphous !raphite is used in +

-etallurgy

$encil $roduction

2efractories Coatings

%ubricants

$aint $roduction

4.Crystalline !raphite is used in+

*atteries %ubricants

!rinding #heels $owder -etallurgy.

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2.3 EAR STUDY AND EAR BEHAVIOUR

#ear is erosion or sideways displacement of material from its HderivativeH

and original position on a solid surface performed by the action of another surface.

#ear is related to interactions between surfaces and more specifically the removal

and deformation of material on a surface as a result of mechanical action of the

opposite surface. The definition of wear may include loss of dimension from

plastic deformation if it is originated at the interface between two sliding surfaces.

'owever, plastic deformation such as yield stress is excluded from the wear

definition if it doesnJt incorporates a relative sliding motion and contact against

another surface despite the possibility for material removal, because it then lac"s

the relative sliding action of another surface. mpact wear is in reality a short

sliding motion where two solid bodies interact at an exceptional short time interval.

$reviously due to the fast execution, the contact found in impact wear was referred

to as an impulse contact by the nomenclature. mpulse can be described as a

mathematical model of a synthesied average on the energy transport between two

travelling solids in opposite converging contact.

2.3.1 T5+e& !# 8ear "e*'ani&"

The study of the processes of wear is part of the discipline of tribology. The

complex nature of wear has delayed its investigations and resulted in isolated

studies towards specific wear mechanisms or processes.0ome commonly referred

to wear mechanisms (or processes) include+

3. Adhesive wear

4. Abrasive wear

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5. 0urface fatigue

. Fretting wear

B. 9rosive wear

CHAPTER 3

EXPERIMENTEL PROCEDURE

3.1 IMPACT TEST

The Charpy impact test, also "nown as the Charpy @notch test, is a

standardied high strainrate test which determines the amount of energy absorbed

by a material during fracture. This absorbed energy is a measure of a givenmaterialJs notch toughness and acts as a tool to study temperaturedependent

ductilebrittle transition. t is widely applied in industry, since it is easy to prepare

and conduct and results can be obtained &uic"ly and cheaply. A disadvantage is

that some results are only comparative.

The apparatus consists of a pendulum of "nown mass and length that is

dropped from a "nown height to impact a notched specimen of material. The

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

the height of the hammer before and after the fracture (energy absorbed by the

fracture event).

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 sie 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 H0tandard methods for 1otched *ar mpact Testing of -etallic

-aterialsH can be found in A0T- where all the aspects of the test and e&uipment

used are described in detail.

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According to A0T- A5G>, the standard specimen sie for Charpy

impact testing is 3> mm P 3>mm P BBmm. 0ubsie specimen sies are+ 3> mm P

G.B mm P BBmm, 3> mm P =.G mm P BB mm, 3> mm P B mm P BB mm, 3> mm P

5.5 mm P BB mm, 3> mm P 4.B mm P BB mm. etails of specimens as per A0T-

A5G> (0tandard Test -ethod and efinitions for -echanical Testing of 0teel

$roducts).

Figure 3.1 I"+a*( Te&( S+e*i"en

3., BRINELL HARDNESS TEST

The *rinell scale characteries the indentation hardness of materials

through the scale of penetration of an indenter, loaded on a material testpiece. t is

one of several definitions of hardness in materials science.

The typical test uses a 3> millimetres (>.5; inch) diametersteel ball as

an indenter with a 5,>>> "gf (4; "1O =,=>> lbf ) force. For softer materials, a

smaller force is usedO for harder materials, a tungsten carbide ball is substituted for

the steel ball. The indentation is measured and hardness calculated as+

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where+

P Q applied force ("gf )

D Q diameter of indenter (mm)

d Q diameter of indentation (mm)

The *'1 can be converted into the ultimate tensile strength (


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3.TENSILE TEST

Tensile testing, also "nown as tension testing,is a fundamental

materials science test in which a sample is sub7ected to a controlled tension until

failure. The results from the test are commonly used to select a material for an

application, for &uality control, and to predict how a material will react under other

types of forces. $roperties 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+ LoungJs modulus,

$oissonJs ratio, yield strength, and strainhardening characteristics.


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grip assures good alignment. Threaded shoulders and grips also assure good

alignment, but the technician must "now to thread each shoulder into the grip at

least one diameterJs length, otherwise the threads can strip before the specimen

fractures.

n 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 specimens may not be exact representation of the whole

wor"piece because the grain structure may be different throughout. n smaller

wor"pieces or when critical parts of the casting must be tested, a wor"piece may be

sacrificed to ma"e the test specimens. For wor"pieces that are machined from bar

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

Figure 3. Ten&i-e Te&( S+e*i"en

A standard specimen is prepared in a round or a s&uare section along

the gauge length, depending on the standard used. *oth ends of the specimens

should have sufficient length and a surface condition such that they are firmly

gripped during testing.

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http://en.wikipedia.org/wiki/Casting_(metalworking)http://en.wikipedia.org/wiki/Forginghttp://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Bar_stockhttp://en.wikipedia.org/wiki/Bar_stockhttp://en.wikipedia.org/wiki/Casting_(metalworking)http://en.wikipedia.org/wiki/Forginghttp://en.wikipedia.org/wiki/Machininghttp://en.wikipedia.org/wiki/Bar_stockhttp://en.wikipedia.org/wiki/Bar_stock


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The test process involves placing the test specimen in the testing

machine and applying tension to it until it fractures. uring the application of

tension, the elongation of the gauge section is recorded against the applied force.

The data is manipulated so that it is not specific to the geometry of the test sample.

The elongation measurement is used to calculate the engineering strain, ε, using the

following e&uation+

where R L is the change in gauge length, L> is the initial gauge length,

and L is the final length. The force measurement is used to calculate the

engineering stress, S, using the following e&uation+

where F is the force and A is the crosssection of the gauge section.

The machine does these calculations as the force increases, so that the data points

can be graphed into a stressstrain curve.

3.0 MICROSTRUCTURE TEST

-icrostructure is defined as the structure of a prepared surface or thin

foil of material as revealed by a microscope above 4BP magnification.The

microstructure of a material (which can be broadly classified into metallic,

polymeric, ceramic and composite) can strongly influence physical properties such

29

http://en.wikipedia.org/wiki/Fracturehttp://en.wikipedia.org/wiki/Elongation_(materials_science)http://en.wikipedia.org/wiki/Deformation_(engineering)http://en.wikipedia.org/wiki/Stress-strain_curvehttp://en.wikipedia.org/wiki/Metallographyhttp://en.wikipedia.org/wiki/Polymerichttp://en.wikipedia.org/wiki/Ceramographyhttp://en.wikipedia.org/wiki/Composite_materialhttp://en.wikipedia.org/wiki/Fracturehttp://en.wikipedia.org/wiki/Elongation_(materials_science)http://en.wikipedia.org/wiki/Deformation_(engineering)http://en.wikipedia.org/wiki/Stress-strain_curvehttp://en.wikipedia.org/wiki/Metallographyhttp://en.wikipedia.org/wiki/Polymerichttp://en.wikipedia.org/wiki/Ceramographyhttp://en.wikipedia.org/wiki/Composite_material


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as strength, toughness, ductility, hardness, corrosion resistance, high/low

temperature behaviour, wear resistance, and so on, which in turn govern the

application of these materials in industrial practice.

3.2 DENSITY TEST

ensity is a ratio expressed by the formula Q# / @ or density e&uals the

weight of material divided by the volume it occupies. A simple example is the

density of water. 9ach cubic foot of water weighs =4. poundsO thus, the density of

water is =4. pounds per cubic foot. n soil testing, density is used to determine the

degree of compaction by comparing the n$lace ensity to the -aximum ensity.

The degree of compaction, expressed as a percent, is then compared to the

specification re&uirement to determine pass or fail. -aximum ensity is a standard

expressed in pounds per cubic foot which is arrived at by applying a standard

compactive effort to a soil mixture under controlled conditions.

ensity measurements are made in different ways depending upon the

physical state of the sample being measured. The volume of a li&uid is commonly

measured in a graduated cylinder. The surface of the li&uid curves upward where it

contacts the cylinder walls. This curved surface is called a meniscus. -easurement

of volume in a graduated cylinder is always made by reading the mar" at the

bottom of the meniscus with the eye positioned at the level of the li&uid surface.

The volume of a solid may be calculated from its dimensions (%x#x'), if the solid

is regular and free of air space. 'owever, if the solid is irregular or contains air

space, its volume must be determined in another way, such as by water

displacement.

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3.2.1 Pr!*eure

3) 6btain clean, dry samples of three different metals. #rite down which

un"nowns you haveO they correspond to the answer "ey.

4) -easure the mass of each metal, using the maximum number of decimal places

allowed by the balance.

5) -easure the volume of each metal separately+

a) Fill a graduated cylinder halfway with sin" water.

b) Tap out any air bubbles.

c) 2ecord initial volume to >.3 ml.

d) Tilt the cylinder gently and slide the metal into it.

t must be submerged.

e) Tap out any air bubbles.

f) 2ecord final volume to >.3 ml.

) #hen finished, carefully pour out the water and metal into your hand. ry the

metal samples and give them to the teacher.

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Figure 3.0 Den&i(5 Te&(

Calculate the density of each metal by the following formula +

Den&i(5 "a&& ?!-u"e.

CHAPTER 4

RESULTS AND DISCUSSIONS

4.1 DENSITY CALCULATION

4.1.1 E6+eri"en(a- Ca-*u-a(i!n

Ma(eria-1

iameter (d) Q 3G.mm

2adius (r) Q .;mm'eight (h) Q 43.=mm

@olume (v) Q r 4h

@ Q B5GB.>=mm5

-ass (m) Q 33.Bg

ensity (U) Q

Q

U Q 4.4>BP3>5 g/mm5

Ma(eria-,+

iameter (d) Q 3G.mm2adius(r) Q .Gmm

'eight (h) Q 44.3mm

@olume (v) Q r 4h

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@ Q B4BB.>Bmm5

-ass (m) Q 33.Bg

ensity (U) Q

Q

U Q 4.4>BP3>5 g/mm5

Ma(eria-+

iameter (d) Q 3=.Bmm2adius(r) Q .4Bmm

'eight (h) Q 43.mm

@olume (v) Q r 4h @ Q ==3.5Gmm5

-ass (m) Q 34.=g

ensity (U) Q

Q

U Q 4.GBP3>5 g/mm5

4.1., T'e!re(i*a- Ca-*u-a(i!n

Ma(eria-1

ensity (U) Q VVWvolume fraction of A=>=3XPWdensity of A=>=3XY ?

VWvolume fraction of fly ashXPWdensity of fly ashXY ?

VWvolume fraction of graphiteXPWdensity of graphiteXYY

Q VW>.;3P4.GX ? W>.>BP3.=X ? W>.>P4.4=XY

Z Q4.=4G"g/mm5

Ma(eria-,+

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Q VW>.;3P4.GX ? W>.3>P3.=X ? W>.>P4.4=XY

U Q4.G;G"g/mm5

Ma(eria-




Q VW>.;3P4.GX ? W>.3BP3.=X ? W>.34P4.4=XY

U Q4.;=4"g/mm5

4., TENSILE TEST

!auge length of the rod (%3) Q =>mm

iameter of the rod (3) Q 3=mm

Tensile load for material3 Q 331/mm4

Tensile load for material4 Q 33=1/mm4

Tensile load for material5 Q 331/mm4

4. IOD IMPACT TEST

imension of wor" piece Q GBP3>P3>mm

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Type of notch Q @notch

1otch angle Q B[

epth of notch Q 4mm

istance of notch from one end Q 4mm

epth of the specimen below the notch Q mm

#idth of the specimen Q 3>mm

Cross section area of the notch point Q >m

Ma(eria-1

mpact strength of the specimen Q

Q >.>GB1/mm4

Ma(eria-,


Q >.>GGB1/mm4

Ma(eria-


Q >.>=GB1/mm4

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4.0 CHARPY IMPACT TEST

0ie of the specimen Q BB

Type of the notch Q < shaped

Total depth of notch Q Bmm

#idth of notch Q 4mm

2adius of semi circle Q 3mm

istance of notch from one end Q 4G.Bmm

epth of the specimen below the notch Q .Bmm

#idth of the specimen Q 3>mm

Ma(eria-1


Q >.3BB331m/mm4

Ma(eria- ,


Q >.35331m/mm4

Ma(eria-

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Q >.3351m/mm4

4.2 ROC7ELL HARDNESS TEST

Ta$-e 4.1 R!*/8e-- 'arne&& (e&( re&u-(&

-aterial scale %oad "g

Type of

theindenter

Test 3 Test 4 Test 5

2oc"well

hardnessnumber

3 * => 3/\ ball B; B BG B

4 * => 3/\ ball = = =4 =

5 * => 3/\ ball = =B =B =B

Ta$-e 4., Den&i(5 ?a-ue (e&( re&u-(&

SPECIMEN NUMBER COMPOSITION LEVEL DENSITY

g"""

3 Al=>=3?4BEflyash?4>Egraphit

e

4.4>4P3>5

4 Al=>=3?B>Eflyash?>Egraphit

e

4.BG=P3>5

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5 Al=>=3?GBEflyash?=>Egraphit

e

4.GBP3>5

4.3 BRINELL HARDNESS TEST

The resistance to indentation or scratch is termed as hardness. Among

various instruments for measurement of hardness, *rinell8s, 2oc"well8s and

@ic"er8s hardness testers are significant in Figureure .2einforcement and matrix

respectively and v and ' stand for volume fraction and hardness respectively) for

composites helps in approximating the hardness values. Among the variants of

reinforcements, the low aspect ratio particle reinforcements are of much significant

in imparting the hardness of the material in which they are dispersed.

Figure 4.1 Harne&& Te&( Ma*'ine

'ardness is probably one of the most used selection factors. The hardness of

materials is often e&uated with wear resistance and durability. This is not a

completely accurate concept but in steels it serves as a measure of abrasion

resistance and strength. There are probably 3>> ways of measuring hardness. n the

early days of metallurgy, heattreated steels were tested for hardness by filing an

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edge. f it did not file, it was hard. -ost presentday hardness tests consist of

pushing a penetrator into the material and measuring the effects. The loading

mechanism varies with the various tests as does the mechanism for measuring the

effect of the indentation.

Ta$-e 4. Brine-- 'arne&& (e&( re&u-(&

SPECIMEN

NUMBER

COMPOSITION LEVEL HARDNESS

%BHN)

3 Al=>=3?4BEflyash?4>Egraphite B;.B5

4 Al=>=3?B>Eflyash?>Egraphite =G.3=

5 Al=>=3?GBEflyash?=>Egraphite G=.3=

4.4 GRAPHICAL REPRESENTATION OF ROC7ELL HARDNESS

TEST

Figure 4., C!"+ari&!n $e(8een #-5 a&' +er*en(age ai(i!n V& Harne&&%RHN)

4.= GRAPHICAL REPRESENTATION OF DENSITY TEST

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Figure 4. C!"+ari&!n $e(8een #-5 a&' +er*en(age ai(i!n V& Den&i(5

4.> GRAPHICAL REPRESENTATION OF IMPACT STRENGTH %IOD

TEST)

Figure 4.0 C!"+ari&!n $e(8een #-5 a&' +er*en(age ai(i!n V& I"+a*(

&(reng(' %I! (e&()

4.1@ GRAPHICAL REPRESENTATION OF IMPACT STRENGTH

%CHARPY TEST)

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Figure 4.2 C!"+ari&!n $e(8een #-5 a&' +er*en(age ai(i!n V& I"+a*(

&(reng(' %C'ar+5 (e&()

4.11 MICROSTRUCTURAL ANALYSIS TEST RESULTS

Ma(eria- 1

Figure 4.3 O+(i*a- "i*r!&*!+e i"age !# ,2 #-5a&'J,@Gra+'i(e +ar(i*u-a(e

rein#!r*e A-3@31 *!"+!&i(e a( ,@@6 "agni#i*a(i!n

41


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Figure 4.4 O+(i*a- "i*r!&*!+e i"age !# ,2 #-5a&'J,@Gra+'i(e +ar(i*u-a(e

rein#!r*e A-3@31 *!"+!&i(e a( 0@@6 "agni#i*a(i!n

Ma(eria-,

Figure 4.= O+(i*a- "i*r!&*!+e i"age !# 2@ #-5a&'J0@Gra+'i(e +ar(i*u-a(e

rein#!r*e A-3@31 *!"+!&i(e a( ,@@6 "agni#i*a(i!n

42


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Figure 4.> O+(i*a- "i*r!&*!+e i"age !# 2@ #-5a&'J0@Gra+'i(e +ar(i*u-a(erein#!r*e A-3@31 *!"+!&i(e a( 0@@6 "agni#i*a(i!n

Ma(eria-

Figure 4.1@ O+(i*a- "i*r!&*!+e i"age !# 42 #-5a&'J3@Gra+'i(e

+ar(i*u-a(e rein#!r*e A-3@31 *!"+!&i(e a( ,@@6 "agni#i*a(i!n

43


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Figure 4.11 O+(i*a- "i*r!&*!+e i"age !# 42 #-5a&'J3@Gra+'i(e

+ar(i*u-a(e rein#!r*e A-3@31 *!"+!&i(e a( 0@@6 "agni#i*a(i!n

CHAPTER =

CONCLUSION

Thus we found that the aerospace and automotive industry needs a material

in low cost of production with high tensile strength and greatest weight ratio.

Through this literature survey we have gained "nowledge in composite materials

for confirming the pro7ect which will fulfill the need of the aerospace and

automotive industries. #e have ideas in the methodology to complete the pro7ect in

low cost of production with high tensile strength and greatest weight ratio.

n many applications, composite materials play a successive role. 0o, our

pro7ect may useful for the aerospace and automotive industries.

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Tribological Characteristics of 0elflubricating AA443Fly ash#hite graphiteComposites nternational ]ournal of 9ngineering and Technology (]9T) @ol B 1o

B page no 3;53; (4>35).

W4X 'emanth l, ^uart (0i64$) reinforced chilled metal matrix composite

(C--C) for automobile applications. -ater es 4>>;O5>+545 ;.

W5X Feng LC, !eng %, Dheng $ ,̂ Dheng DD, #ang !0. Fabrication and

characteristic of Albased hybrid composite reinforced with tungsten oxide particle

and aluminum borate whis"er by s&ueee casting. -ater es4>>O4;+4>45=.

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composites. -ater 0ci 9ng A4>>;OB>4+;;3>=.

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WBX 2ohatgi, $.M., aoud, A., 0chult, *.F., $uri, T., 4>>;. -icrostructure and

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W=X Malaiselvan M, -urugan 1, $arameswaran 0. $roduction and characteriation

of AA=>=3*C stir cast composite. -ater es4>33O54+>>;

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the stir casting method. ] -ater $rocess Technol3;;;O;4 ;5+3 G.

W;X *asavara7u .0, Arasu"umar . M, 0tudies on -echanical properties and

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W3>X 'arish M.!arg , Metan @erma , Ala"esh -anna , 2a7esh Mumar ,'ybrid-etal -atrix Composites and further improvement in their machinability,

@ol.3,ssue 3 +5=,-ay]une(4>34).

Tribological and Mechanical Behaviour of Hybrid Metal Matrix Composite

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